"Server sent an invalid response" Error on starting assessments
Opened this issue · 3 comments
I am having an issue where students are getting the "Server sent an invalid response" error on resuming assessments. The error persists over multiple assessments but for seemingly random users.
Code follows. My apologies for the trash formatting.
<br />
<b>Warning</b>: max(): Array must contain at least one element in <b>/home/customer/www/calculus.studio/public_html/IMathAS/assess2/AssessRecord.php</b> on line <b>1669</b><br />
{"prev_attempts":[],"scored_attempt":{"score":36.7000000000000028421709430404007434844970703125,"kept":0},"available":"yes","startdate":1601999831,"enddate":1603688400,"submitby":"by_question","timelimit":0,"timelimit_type":"kick_out","showscores":"during","intro":"<h1 class=\"page-title\">Functions, Variables, and Graphs <\/h1>\r\n<h1 class=\"page-title\"><small>Function Notation<\/small><\/h1>\r\n<p><strong>Read <a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Section 3.11 Function Notation<\/a> before beginning the assessment. <\/strong><\/p>\r\n<p> <\/p>","interquestion_text":[],"resources":[],"help_features":{"message":false,"forum":3},"points_possible":80,"showcat":1,"enddate_in":450750,"displaymethod":"full","preview_all":false,"show_results":true,"has_active_attempt":true,"questions":[{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":98,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":10,"gbrawscore":1,"try":1,"parts":[{"try":1,"score":10,"rawscore":1,"penalties":[],"req_manual":false,"points_possible":10}],"status":"correct","score":10,"rawscore":1,"seed":397,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.1<\/a> Meaning of p(w) <\/strong><\/p>\n<p><span style=\"font-weight: 400;\">Samuel’s swimming pool has sloped walls that are rounded at the bottom so that the area of the water's top surface varies with the height of water in the pool. Let <em>p<\/em> be a function that relates the water’s height in the pool in meters with the pool’s surface area in square meters. Let <em>w<\/em> represent the water’s height in meters.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Explain the meaning of the term <\/span><em><span style=\"font-weight: 400;\">p<\/span><\/em><span style=\"font-weight: 400;\">(<\/span><em><span style=\"font-weight: 400;\">w<\/span><\/em><span style=\"font-weight: 400;\">)<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><div class=\"ansgrn clearfix\" id=\"qnwrap0\" style=\"display:block\" role=group aria-label=\"Question 1\"><ul class=nomark><li><input class=\"unind\" type=radio name=qn0 value=0 id=\"qn0-0\" CHECKED \/><label for=\"qn0-0\"> The surface area in square meters, when the water height is wmeters<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn0 value=1 id=\"qn0-1\" \/><label for=\"qn0-1\"> The value ofpyou get when you substitute in a value ofwinto a formula<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn0 value=2 id=\"qn0-2\" \/><label for=\"qn0-2\"> The height in meters, when the surface area iswsquare meters<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn0 value=3 id=\"qn0-3\" \/><label for=\"qn0-3\"> An amount of height, specificallywmeters of water height<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn0 value=4 id=\"qn0-4\" \/><label for=\"qn0-4\"> An amount of surface area, specificallywsquare meters of water surface area<\/label><\/li> \n<\/ul>\n<\/div><\/span><\/p><div class=\"autoshowans\"><div><div><input id=\"showansbtn0\" class=\"sabtn\" type=button value=\"Show Answer\" \/> <span id=\"ans0\" class=\"hidden\"> The surface area in square meters, when the water height isw meters<\/span>\n<\/div><\/div><\/div>\n<\/div>\n","jsparams":{"0":{"qtype":"choices"},"helps":[]},"answeights":[1],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":99,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":10,"gbrawscore":1,"try":2,"parts":[{"try":2,"score":10,"rawscore":1,"penalties":[],"req_manual":false,"points_possible":10}],"status":"correct","score":10,"rawscore":1,"seed":4014,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.2<\/a> Criteria for Function<\/strong><\/p>\n<p><span style=\"font-weight: 400;\">Samuel’s swimming pool has sloped walls that are rounded at the bottom so that the area of the water's top surface varies with the amount of water in the pool. Let <\/span><em><span style=\"font-weight: 400;\">p<\/span><\/em><span style=\"font-weight: 400;\"> be a function that relates the water’s height in the pool in meters with the pool’s surface area in square meters. Let <\/span><em><span style=\"font-weight: 400;\">w<\/span><\/em><span style=\"font-weight: 400;\"> represent the water’s height in meters. Then <\/span><em><span style=\"font-weight: 400;\">p<\/span><\/em><span style=\"font-weight: 400;\">(<\/span><em><span style=\"font-weight: 400;\">w<\/span><\/em><span style=\"font-weight: 400;\">) represents the water’s surface area in square meters at height <\/span><em><span style=\"font-weight: 400;\">w<\/span><\/em><span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Why does <em><span style=\"font-weight: 400;\">p<\/span><\/em><span style=\"font-weight: 400;\"> meet the definition of being a function?<\/span><\/span><\/p><div class=\"toppad\"><div class=\"ansgrn clearfix\" id=\"qnwrap1\" style=\"display:block\" role=group aria-label=\"Question 2\"><ul class=nomark><li><input class=\"unind\" type=radio name=qn1 value=0 id=\"qn1-0\" \/><label for=\"qn1-0\">Because as the surface area (m^2) of Sam's pool water decreases, so does the height of water (m) in Sam's pool<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn1 value=1 id=\"qn1-1\" CHECKED \/><label for=\"qn1-1\">Because for every height of water (m) in Sam's pool, there is only one surface area (m^2) of Sam's pool water<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn1 value=2 id=\"qn1-2\" \/><label for=\"qn1-2\">Because the surface area (m^2) of Sam's pool water increases nonlinearly with respect to the height of water (m) in Sam's pool (because of the rounded edges at the bottom)<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn1 value=3 id=\"qn1-3\" \/><label for=\"qn1-3\">Because as the height of water (m) in Sam's pool increases, so does the surface area (m^2) of Sam's pool water<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn1 value=4 id=\"qn1-4\" \/><label for=\"qn1-4\">Because for every surface area (m^2) of Sam's pool water, there is only one height of water (m) in Sam's pool<\/label><\/li> \n<\/ul>\n<\/div><\/div>\n<div class=\"autoshowans\"><div><\/div><\/div>\n<\/div>\n","jsparams":{"1":{"qtype":"choices"},"helps":[]},"answeights":[1],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":100,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":10,"gbrawscore":1,"try":10,"parts":[{"try":10,"score":10,"rawscore":1,"penalties":[],"req_manual":false,"points_possible":10}],"status":"correct","score":10,"rawscore":1,"seed":405,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.3<\/a> Sam's Pool Expressions<\/strong><\/p>\n<p><span style=\"font-weight: 400;\">Samuel’s swimming pool has sloped walls that are rounded at the bottom so that the area of the water's top surface varies with the amount of water in the pool. Let p <\/span> <span style=\"font-weight: 400;\">be a function that relates the water’s height in the pool in meters with the pool’s surface area in square meters. Let w <\/span> <span style=\"font-weight: 400;\">represent the water’s height in meters. Then p(w) <\/span> <span style=\"font-weight: 400;\">represents the water’s surface area in square meters at water height w <\/span> <span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Match each algebraic statement with its meaning in the context of Sam’s pool.<\/span><\/p><div class=\"toppad\"><div id=\"qnwrap2\" role=\"group\" class=\"ansgrn\" aria-label=\"Question 3\"><div class=\"match\" >\n<ul class=\"nomark\">\n<li class=\"nowrap\"><select name=\"qn2-0\" id=\"qn2-0\"><option value=\"-\" >-<\/option><option value=\"0\" selected=\"1\">a<\/option><option value=\"1\" >b<\/option><option value=\"2\" >c<\/option><option value=\"3\" >d<\/option><option value=\"4\" >e<\/option><option value=\"5\" >f<\/option><option value=\"6\" >g<\/option><option value=\"7\" >h<\/option><option value=\"8\" >i<\/option><option value=\"9\" >j<\/option><\/select> <label for=\"qn2-0\">p(1+a)-p(a)<\/label><\/li>\n<li class=\"nowrap\"><select name=\"qn2-1\" id=\"qn2-1\"><option value=\"-\" >-<\/option><option value=\"0\" >a<\/option><option value=\"1\" >b<\/option><option value=\"2\" selected=\"1\">c<\/option><option value=\"3\" >d<\/option><option value=\"4\" >e<\/option><option value=\"5\" >f<\/option><option value=\"6\" >g<\/option><option value=\"7\" >h<\/option><option value=\"8\" >i<\/option><option value=\"9\" >j<\/option><\/select> <label for=\"qn2-1\">p(1.8)<\/label><\/li>\n<li class=\"nowrap\"><select name=\"qn2-2\" id=\"qn2-2\"><option value=\"-\" >-<\/option><option value=\"0\" >a<\/option><option value=\"1\" selected=\"1\">b<\/option><option value=\"2\" >c<\/option><option value=\"3\" >d<\/option><option value=\"4\" >e<\/option><option value=\"5\" >f<\/option><option value=\"6\" >g<\/option><option value=\"7\" >h<\/option><option value=\"8\" >i<\/option><option value=\"9\" >j<\/option><\/select> <label for=\"qn2-2\">p(b+0.5)-p(b)<\/label><\/li>\n<li><select name=\"qn2-3\" id=\"qn2-3\"><option value=\"-\" >-<\/option><option value=\"0\" >a<\/option><option value=\"1\" >b<\/option><option value=\"2\" >c<\/option><option value=\"3\" >d<\/option><option value=\"4\" >e<\/option><option value=\"5\" >f<\/option><option value=\"6\" selected=\"1\">g<\/option><option value=\"7\" >h<\/option><option value=\"8\" >i<\/option><option value=\"9\" >j<\/option><\/select> <label for=\"qn2-3\">p(c)=14.3 for some number c<\/label><\/li>\n<li class=\"nowrap\"><select name=\"qn2-4\" id=\"qn2-4\"><option value=\"-\" >-<\/option><option value=\"0\" >a<\/option><option value=\"1\" >b<\/option><option value=\"2\" >c<\/option><option value=\"3\" >d<\/option><option value=\"4\" selected=\"1\">e<\/option><option value=\"5\" >f<\/option><option value=\"6\" >g<\/option><option value=\"7\" >h<\/option><option value=\"8\" >i<\/option><option value=\"9\" >j<\/option><\/select> <label for=\"qn2-4\">p(0.9)-p(0.7)<\/label><\/li>\n<\/ul>\n<\/div><div class=\"match\" >\n<ol class=lalpha>\n<li>The change in surface area of Sam's pool water (m^2) when the water height increases 1 meter above a meters<\/li>\n<li>The change in surface area of Sam's pool water (m^2) when the water height increases from btob+0.5 meters<\/li>\n<li>The surface area (m^2) of Sam's pool water, when the height is 1.8 meters<\/li>\n<li>The change in height of the water in Sam's pool (meters) when the surface area is 0.5 m^2<\/li>\n<li>The change in surface area of Sam's pool water (m^2) when the water height increases from 0.7 to 0.9 meters<\/li>\n<li>The height (m) of water in Sam's pool, when the surface area is 1.8 m^2<\/li>\n<li>The surface area of Sam's pool water is 14.3 m^2when the height of the water iscmeters<\/li>\n<li>The change in height of the water in Sam's pool (meters) when the surface area is 0.2m^2<\/li>\n<li>The height of the water in Sam's pool is 14.3 meters when the surface area of the water is c m^2<\/li>\n<li>The change in height of the water in Sam's pool (meters) when the surface area changes by 1 meter<\/li>\n<\/ol><\/div><div class=spacer> <\/div><\/div><\/div>\n<div class=\"autoshowans\"><div><div><input id=\"showansbtn2\" class=\"sabtn\" type=button value=\"Show Answer\" \/> <span id=\"ans2\" class=\"hidden\">a c b g e <\/span>\n<\/div><\/div><\/div>\n<\/div>\n","jsparams":{"2":{"qtype":"matching"},"helps":[]},"answeights":[1],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":101,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":0,"gbrawscore":0,"try":1,"parts":[{"try":1,"score":0,"rawscore":0,"penalties":[],"req_manual":true,"points_possible":10}],"status":"incorrect","score":0,"rawscore":0,"seed":4311,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.4<\/a> Is p(0.9)-p(0.7) = p(0.2) ?<\/strong><\/p>\n<p>Samuel’s swimming pool has sloped walls that are rounded at the bottom so that the area of the water's top surface varies with the amount of water in the pool. Let <em>p<\/em> be a function that relates the water’s height in the pool in meters with the pool’s surface area in square meters. Let <em>w<\/em> represent the water’s height in meters. Then <em>p<\/em>(<em>w<\/em>) represents the water’s surface area in square meters at height <em>w<\/em>.<\/p>\n<p>A student in another class claimed that p(0.9)-p(0.7)=p(0.2) . Do you agree? Explain.<\/p><div class=\"toppad\"><textarea rows=\"5\" name=\"qn4000\" id=\"qn4000\" cols=\"50\" aria-label=\"Question 4\" >Yes I agree because this equation represents the change in surface area of Sam's pool water (m^2) when the water height increases from 0.7 to 0.9 meters. So this equation accurately represent the water's surface area in square meters at height w.<\/textarea>\n<\/div>\n<div class=spacer> <\/div>\n\n<\/div>\n","jsparams":{"4000":{"qtype":"essay"},"helps":[]},"answeights":[1],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":102,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":3.3300000000000000710542735760100185871124267578125,"gbrawscore":0.333299999999999985167420391007908619940280914306640625,"try":1,"parts":[{"try":1,"score":1.6670000000000000373034936274052597582340240478515625,"rawscore":1,"penalties":[],"req_manual":false,"points_possible":1.6670000000000000373034936274052597582340240478515625},{"try":1,"score":1.6670000000000000373034936274052597582340240478515625,"rawscore":1,"penalties":[],"req_manual":false,"points_possible":1.6670000000000000373034936274052597582340240478515625},{"try":6,"score":0,"rawscore":0,"penalties":[],"req_manual":false,"points_possible":1.6670000000000000373034936274052597582340240478515625},{"try":3,"score":0,"rawscore":0,"penalties":[],"req_manual":false,"points_possible":1.6670000000000000373034936274052597582340240478515625},{"try":1,"score":0,"rawscore":0,"penalties":[],"req_manual":false,"points_possible":1.6670000000000000373034936274052597582340240478515625},{"try":1,"score":0,"rawscore":0,"penalties":[],"req_manual":false,"points_possible":1.6670000000000000373034936274052597582340240478515625}],"status":"partial","score":3.3300000000000000710542735760100185871124267578125,"rawscore":0.333299999999999985167420391007908619940280914306640625,"seed":7505,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><span style=\"text-decoration: underline;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.5<\/a> Unser-Montoya Intro Problem<\/strong><\/span><\/p>\n<p style=\"text-align: center;\"><em><strong>Note: This problem must be submitted before you can do any other problems in this assignment that refer to Unser or Montoya.<\/strong><\/em><\/p>\n<p><span style=\"font-weight: 400;\">Al Unser won the Indianapolis 500-mile race in 1987. Juan Pablo Montoya won the Indianapolis 500-mile race in 2015. Unser completed his race in 3.083089 hours. Montoya completed his race in 3.099033 hours. Imagine that they drove their exact races against each other and that the race ended when the winner crossed the finish line. Let <\/span><em><span style=\"font-weight: 400;\">t<\/span><\/em><span style=\"font-weight: 400;\"> represent the number of hours since their imaginary race started.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">a) Choose a letter to represent the function that gives Unser’s distance with respect to time <\/span><em><span style=\"font-weight: 400;\">during the race<\/span><\/em><span style=\"font-weight: 400;\">: <\/span><span style=\"font-weight: 400;\"><input type=\"text\" size=\"20\" name=\"qn5000\" id=\"qn5000\" value=\"x\" autocomplete=\"off\" aria-label=\"Question 5 Part 1 of 6\" class=\"text ansgrn\" \/><\/span><\/p>\n<p><span style=\"font-weight: 400;\">b) Choose a letter to represent the function that gives Montoya’s distance with respect to time <\/span><em><span style=\"font-weight: 400;\">during the race<\/span><\/em><span style=\"font-weight: 400;\">: <input type=\"text\" size=\"20\" name=\"qn5001\" id=\"qn5001\" value=\"y\" autocomplete=\"off\" aria-label=\"Question 5 Part 2 of 6\" class=\"text ansgrn\" \/><\/span><span style=\"font-weight: 400;\"><br \/><\/span><\/p>\n<p><span style=\"font-weight: 400;\">c) Use function notation to represent the distance that Unser traveled, in relation to the number of hours since the race began <input type=\"text\" size=\"20\" name=\"qn5002\" id=\"qn5002\" value=\"(x+y)-x\" autocomplete=\"off\" aria-label=\"Question 5 Part 3 of 6\" class=\"text ansred\" \/>. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">Represent the domain of the independent variable (using interval notation): <input type=\"text\" size=\"20\" name=\"qn5003\" id=\"qn5003\" value=\"(-oo,oo)\" autocomplete=\"off\" aria-label=\"Question 5 Part 4 of 6\" class=\"text ansred\" \/><span id=p5003><\/span> .<\/span><\/p>\n<p><span style=\"font-weight: 400;\">d) Use function notation to represent the distance that Montoya traveled, in relation to the number of hours since the race began <input type=\"text\" size=\"20\" name=\"qn5004\" id=\"qn5004\" value=\"x-(x-y)\" autocomplete=\"off\" aria-label=\"Question 5 Part 5 of 6\" class=\"text ansred\" \/>. <\/span><\/p>\n<p><span style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Represent the domain of the independent variable (using interval notation):<\/span> <input type=\"text\" size=\"20\" name=\"qn5005\" id=\"qn5005\" value=\"(-oo,oo)\" autocomplete=\"off\" aria-label=\"Question 5 Part 6 of 6\" class=\"text ansred\" \/><span id=p5005><\/span> .<\/span><\/p><div class=\"autoshowans\"><div><div><input id=\"showansbtn4-0\" class=\"sabtn\" type=button value=\"Show Answer\" \/> <span id=\"ans4-0\" class=\"hidden\">x<\/span>\n<\/div><\/div><div><div><input id=\"showansbtn4-1\" class=\"sabtn\" type=button value=\"Show Answer\" \/> <span id=\"ans4-1\" class=\"hidden\">y<\/span>\n<\/div><\/div><\/div>\n<\/div>\n","jsparams":{"5000":{"tip":"Enter text","longtip":"Enter your answer as letters. Examples: A B C, linear, a cat","calcformat":"","qtype":"string"},"5001":{"tip":"Enter text","longtip":"Enter your answer as letters. Examples: A B C, linear, a cat","calcformat":"","qtype":"string"},"5002":{"tip":"Enter text","longtip":"Enter your answer as letters. Examples: A B C, linear, a cat","calcformat":"","qtype":"string"},"5003":{"tip":"Enter an interval using interval notation","longtip":"Enter your answer using interval notation. Example: [2.1,5.6172) <br\/>Use U for union to combine intervals. Example: (-oo,2] U [4,oo)<br\/>Enter DNE for an empty set. Use oo to enter Infinity.","calcformat":"decimal","helper":1,"qtype":"interval"},"5004":{"tip":"Enter text","longtip":"Enter your answer as letters. Examples: A B C, linear, a cat","calcformat":"","qtype":"string"},"5005":{"tip":"Enter an interval using interval notation","longtip":"Enter your answer using interval notation. Example: [2.1,5.6172) <br\/>Use U for union to combine intervals. Example: (-oo,2] U [4,oo)<br\/>Enter DNE for an empty set. Use oo to enter Infinity.","calcformat":"decimal","helper":1,"qtype":"interval"},"helps":[]},"answeights":[1,1,1,1,1,1],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":103,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":3.339999999999999857891452847979962825775146484375,"gbrawscore":0.334000000000000019095836023552692495286464691162109375,"try":0,"parts":[{"try":0,"score":0,"points_possible":2},{"try":0,"score":0,"points_possible":2},{"try":0,"score":0,"points_possible":2},{"try":4,"score":2,"rawscore":1,"penalties":[],"req_manual":false,"points_possible":2},{"try":6,"score":1.3400000000000000799360577730112709105014801025390625,"rawscore":0.67000000000000003996802888650563545525074005126953125,"penalties":[],"req_manual":false,"points_possible":2}],"status":"unattempted","score":3.339999999999999857891452847979962825775146484375,"rawscore":0.334000000000000019095836023552692495286464691162109375,"seed":8074,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.6<\/a> Unser Distances<\/strong><\/p>\n<p><em><strong>Note: If you haven’t done the Unser-Montoya Intro problem yet, please go do that first or the computer cannot display this problem correctly (or grade it correctly)!<\/strong><\/em><\/p>\n<p>Al Unser won the Indianapolis 500-mile race in 1987. Juan Pablo Montoya won the Indianapolis 500-mile race in 2015. Unser completed his race in 3.083089 hours. Montoya completed his race in 3.099033 hours. Imagine that they drove their exact races against each other and that the race ended when the winner crossed the finish line. This question concerns the imaginary race.<\/p>\n<p>Recall that, in the Unser-Montoya Intro Problem, you created the following definitions: <span style=\"font-weight: 400;\">for all 0<=t<=3.083089, y(t) is the number of miles Montoya has traveled thours after the race began, andx(t) is the number of miles Unser has traveled t hours after the race began. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">Use function notation to represent the distance that Unser traveled in the first 0.09 hours of the race.<\/span><\/p>\n<p><input type=\"text\" size=\"20\" name=\"qn6000\" id=\"qn6000\" value=\"\" autocomplete=\"off\" aria-label=\"Question 6 Part 1 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn6000\" value=\"Preview\"\/> \n<span id=p6000><\/span>\n<\/p>\n<p><span style=\"font-weight: 400;\"> Use function notation to represent the distance that Montoya traveled in the first 97 <\/span><strong>minutes<\/strong><span style=\"font-weight: 400;\"> of the race<\/span><\/p>\n<p><input type=\"text\" size=\"20\" name=\"qn6001\" id=\"qn6001\" value=\"\" autocomplete=\"off\" aria-label=\"Question 6 Part 2 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn6001\" value=\"Preview\"\/> \n<span id=p6001><\/span>\n <\/p>\n<p><span style=\"font-weight: 400;\">Use function notation to represent the number of miles that Unser traveled from 1.192 hours after the race began to 2.013 hours after the race began.<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><input type=\"text\" size=\"20\" name=\"qn6002\" id=\"qn6002\" value=\"\" autocomplete=\"off\" aria-label=\"Question 6 Part 3 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn6002\" value=\"Preview\"\/> \n<span id=p6002><\/span>\n<\/span><\/p>\n<p><span style=\"font-weight: 400;\">What must be true about the value of x(2.013-1.192)?<\/span><\/p>\n<p><div class=\"ansgrn clearfix\" id=\"qnwrap6003\" style=\"display:block\" role=group aria-label=\"Question 6 Part 4 of 5 Select one or more answers\"><ul class=nomark><li><input class=\"unind\" type=checkbox name=\"qn6003[0]\" value=0 id=\"qn6003-0\" \/><label for=\"qn6003-0\">It represents how far Unser traveled from 1.192 to 2.013 hours<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6003[1]\" value=1 id=\"qn6003-1\" \/><label for=\"qn6003-1\"> Its value is k*0.821, where kis Unser's average speed<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6003[2]\" value=2 id=\"qn6003-2\" checked \/><label for=\"qn6003-2\"> It represents how far Unser has traveled after the first 0.821 hours<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6003[3]\" value=3 id=\"qn6003-3\" \/><label for=\"qn6003-3\"> It is the same value asx(2.013)-x(1.192)<\/label><\/li> \n<\/ul>\n<\/div><\/p>\n<p>Which of the following represent(s) the number of miles Montoya traveled in a one-hour time period?<\/p>\n<p><div class=\"ansyel clearfix\" id=\"qnwrap6004\" style=\"display:block\" role=group aria-label=\"Question 6 Part 5 of 5 Select one or more answers\"><ul class=nomark><li><input class=\"unind\" type=checkbox name=\"qn6004[0]\" value=0 id=\"qn6004-0\" \/><label for=\"qn6004-0\">y(x+1)<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6004[1]\" value=1 id=\"qn6004-1\" \/><label for=\"qn6004-1\">y(x+1)-y(x)<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6004[2]\" value=2 id=\"qn6004-2\" checked \/><label for=\"qn6004-2\">y(1)<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6004[3]\" value=3 id=\"qn6004-3\" \/><label for=\"qn6004-3\">y(x-1)<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6004[4]\" value=4 id=\"qn6004-4\" \/><label for=\"qn6004-4\">y(x)-y(1)<\/label><\/li> \n<li><input class=\"unind\" type=checkbox name=\"qn6004[5]\" value=5 id=\"qn6004-5\" \/><label for=\"qn6004-5\">y(x)-y(x-1)<\/label><\/li> \n<\/ul>\n<\/div><\/p>\n<p><span style=\"font-weight: 400;\"> <\/span><\/p><div class=\"autoshowans\"><div><div><input id=\"showansbtn5-3\" class=\"sabtn\" type=button value=\"Show Answer\" \/> <span id=\"ans5-3\" class=\"hidden\"><br\/> It represents how far Unser has traveled after the first 0.821 hours<\/span>\n<\/div><\/div><\/div>\n<\/div>\n","jsparams":{"6000":{"tip":"Enter an algebraic expression","longtip":"Enter your answer as an expression. Example: 3x^2+1, x\/5, (a+b)\/c\n<br\/>Be sure your variables match those in the question","helper":1,"preview":1,"calcformat":"","vars":["y","x"],"fvars":["y","x"],"domain":[[-10,10,false],[-10,10,false]],"qtype":"numfunc"},"6001":{"tip":"Enter an algebraic expression","longtip":"Enter your answer as an expression. Example: 3x^2+1, x\/5, (a+b)\/c\n<br\/>Be sure your variables match those in the question","helper":1,"preview":1,"calcformat":"","vars":["y","x"],"fvars":["y","x"],"domain":[[-10,10,false],[-10,10,false]],"qtype":"numfunc"},"6002":{"tip":"Enter an algebraic expression","longtip":"Enter your answer as an expression. Example: 3x^2+1, x\/5, (a+b)\/c\n<br\/>Be sure your variables match those in the question","helper":1,"preview":1,"calcformat":"","vars":["y","x"],"fvars":["y","x"],"domain":[[-10,10,false],[-10,10,false]],"qtype":"numfunc"},"6003":{"qtype":"multans"},"6004":{"qtype":"multans"},"helps":[]},"answeights":[1,1,1,1,1],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":104,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":0,"gbrawscore":0,"try":0,"parts":[{"try":0,"score":0,"rawscore":0}],"status":"unattempted","score":0,"rawscore":0,"seed":2995,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.7-8<\/a>* Unser Finish Line<\/strong><\/p>\n<p><em><strong>Note: If you haven’t done the Unser-Montoya Intro problem yet, please go do that first or the computer cannot display this problem correctly (or grade it correctly)!<\/strong><\/em><\/p>\n<p>Al Unser won the Indianapolis 500-mile race in 1987. Juan Pablo Montoya won the Indianapolis 500-mile race in 2015. Unser completed his race in 3.083089 hours. Montoya completed his race in 3.099033 hours. Imagine that they drove their exact races against each other and that the race ended when the winner crossed the finish line. This question concerns the imaginary race.<\/p>\n<p><span style=\"font-weight: 400;\">Recall that, in the Unser-Montoya Intro Problem, you created the following definitions: for all 0<=t<=3.083089, y(t) is the number of miles Montoya has traveled thours after the race began, andx(t)is the number of miles Unser has traveledthours after the race began.<\/span> <\/p>\n<p><span style=\"font-weight: 400;\"><strong>1(a)<\/strong> Use function notation to write an expression to represent the number of miles between Unser and Montoya when Unser crossed the finish line. <input type=\"text\" size=\"20\" name=\"qn7000\" id=\"qn7000\" value=\"\" autocomplete=\"off\" aria-label=\"Question 7 Part 1 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn7000\" value=\"Preview\"\/> \n<span id=p7000><\/span>\n<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><strong>1(b) <\/strong>Explain how what you wrote represents what you claim. <textarea rows=\"5\" name=\"qn7001\" id=\"qn7001\" cols=\"50\" aria-label=\"Question 7 Part 2 of 5\" ><\/textarea>\n<br \/><\/span><\/p>\n<p><strong>1(c)<\/strong> <span style=\"font-weight: 400;\">During the race, is Unser always ahead of Montoya? <div class=\"clearfix\" id=\"qnwrap7002\" style=\"display:block\" role=group aria-label=\"Question 7 Part 3 of 5\"><ul class=nomark><li><input class=\"unind\" type=radio name=qn7002 value=0 id=\"qn7002-0\" \/><label for=\"qn7002-0\">No<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn7002 value=1 id=\"qn7002-1\" \/><label for=\"qn7002-1\">Yes<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn7002 value=2 id=\"qn7002-2\" \/><label for=\"qn7002-2\">Not enough information to determine<\/label><\/li> \n<\/ul>\n<\/div><\/span><\/p>\n<p><span style=\"font-weight: 400;\"><strong>2(a) <\/strong>Use function notation to represent the number of miles between Montoya and Unserthours after the race began. Hint: make sure your expression works no matter who is ahead. <input type=\"text\" size=\"20\" name=\"qn7003\" id=\"qn7003\" value=\"\" autocomplete=\"off\" aria-label=\"Question 7 Part 4 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn7003\" value=\"Preview\"\/> \n<span id=p7003><\/span>\n<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><strong>2(b) <\/strong>What interval represents the values oft for which your answer to 2(a) makes sense? Enter your answer using interval notation. Example: [2,5] <input type=\"text\" size=\"20\" name=\"qn7004\" id=\"qn7004\" value=\"\" autocomplete=\"off\" aria-label=\"Question 7 Part 5 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn7004\" value=\"Preview\" \/> \n<span id=p7004><\/span> <\/span><\/p>\n<\/div>\n","jsparams":{"7000":{"tip":"Enter an algebraic expression","longtip":"Enter your answer as an expression. Example: 3x^2+1, x\/5, (a+b)\/c\n<br\/>Be sure your variables match those in the question","helper":1,"preview":1,"calcformat":"","vars":["x","y","t"],"fvars":[],"domain":[[-10,10,false],[-10,10,false],[-10,10,false]],"qtype":"numfunc"},"7001":{"qtype":"essay"},"7002":{"qtype":"choices"},"7003":{"tip":"Enter an algebraic expression","longtip":"Enter your answer as an expression. Example: 3x^2+1, x\/5, (a+b)\/c\n<br\/>Be sure your variables match those in the question","helper":1,"preview":1,"calcformat":"","vars":["x","y","t"],"fvars":[],"domain":[[-10,10,false],[-10,10,false],[-10,10,false]],"qtype":"numfunc"},"7004":{"tip":"Enter an interval using interval notation","longtip":"Enter your answer using interval notation. Example: [2,5) <br\/>Use U for union to combine intervals. Example: (-oo,2] U [4,oo)<br\/>Enter each value as a number (like 5, -3, 2.2172) or as a calculation (like 5\/3, 2^3, 5+4)<br\/>Enter DNE for an empty set. Use oo to enter Infinity.","helper":1,"calcformat":"","preview":1,"qtype":"calcinterval"},"helps":[]},"answeights":["0.25","0","0.25","0.25","0.25"],"usedautosave":[],"work":"","errors":[]},{"tries_max":100,"retry_penalty":0,"retry_penalty_after":1,"showans":"after_lastattempt","showans_aftern":0,"points_possible":10,"questionsetid":105,"category":"","withdrawn":0,"jump_to_answer":false,"showwork":0,"regens_max":1,"regen":0,"gbscore":0,"gbrawscore":0,"try":0,"parts":[{"try":0,"score":0,"rawscore":0}],"status":"unattempted","score":0,"rawscore":0,"seed":4505,"singlescore":false,"info":true,"html":"<div class=\"question\" role=region aria-label=\"Question\">\n<p style=\"text-align: center;\"><strong><a href=\"http:\/\/patthompson.net\/ThompsonCalc\/section_3_11.html\" target=\"_blank\" rel=\"noopener\">Exercise 3.11.9-11*<\/a> Unser Times<\/strong><\/p>\n<p><em><strong>Note: If you haven’t done the Unser-Montoya Intro problem yet, please go do that first or the computer cannot display this problem correctly (or grade it correctly)!<\/strong><\/em><\/p>\n<p><span style=\"font-weight: 400;\">Al Unser won the Indianapolis 500-mile race in 1987. Juan Pablo Montoya won the Indianapolis 500-mile race in 2015. Unser completed his race in 3.083089 hours. Montoya completed his race in 3.099033 hours. Imagine that they drove their exact races against each other and that the race ended when the winner crossed the finish line. This question concerns the imaginary race. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">Recall that, in the Unser-Montoya Intro Problem, you created the following definitions: for all 0<=t<=3.083089, y(t) is the number of miles Montoya has traveled t hours after the race began, and x(t)is the number of miles Unser has traveledt hours after the race began. <\/span><\/p>\n<p><span style=\"font-weight: 400;\"><strong>(a) <\/strong>Represent those times when Unser was ahead of Montoya. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">All 0<=t<=3.083089 such that <input type=\"text\" size=\"20\" name=\"qn8000\" id=\"qn8000\" value=\"\" autocomplete=\"off\" aria-label=\"Question 8 Part 1 of 5\" class=\"text\" \/><\/span><\/p>\n<p><span style=\"font-weight: 400;\"><strong>(b) <\/strong><span style=\"font-weight: 400;\">Explain how what you wrote for part (a) represents what you claim. <\/span><\/span><\/p>\n<p><span style=\"font-weight: 400;\"><span style=\"font-weight: 400;\"><textarea rows=\"5\" name=\"qn8001\" id=\"qn8001\" cols=\"50\" aria-label=\"Question 8 Part 2 of 5\" ><\/textarea>\n<\/span><\/span><\/p>\n<p><span style=\"font-weight: 400;\"><span style=\"font-weight: 400;\"><strong>(c)<\/strong><span style=\"font-weight: 400;\">Represent the moment(s) in time when Unser was exactly 0.23 miles ahead of Montoya. <\/span><\/span><\/span><\/p>\n<p><span style=\"font-weight: 400;\"><span style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">All 0<=t<=3.083089 such that <input type=\"text\" size=\"20\" name=\"qn8002\" id=\"qn8002\" value=\"\" autocomplete=\"off\" aria-label=\"Question 8 Part 3 of 5\" class=\"text\" \/><input type=button class=btn id=\"pbtn8002\" value=\"Preview\"\/> \n<span id=p8002><\/span>\n<\/span><\/span><\/span><\/p>\n<p><strong>(d) <\/strong><span style=\"font-weight: 400;\">Explain how what you wrote for part (c) represents what you claim.<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><textarea rows=\"5\" name=\"qn8003\" id=\"qn8003\" cols=\"50\" aria-label=\"Question 8 Part 4 of 5\" ><\/textarea>\n<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><strong>(e)<\/strong> Is it possible that your answer for part (c) has more than one solution? Why or why not?<\/span><\/p>\n<p><span style=\"font-weight: 400;\"><div class=\"clearfix\" id=\"qnwrap8004\" style=\"display:block\" role=group aria-label=\"Question 8 Part 5 of 5\"><ul class=nomark><li><input class=\"unind\" type=radio name=qn8004 value=0 id=\"qn8004-0\" \/><label for=\"qn8004-0\">No, because Unser is always ahead of Montoya<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn8004 value=1 id=\"qn8004-1\" \/><label for=\"qn8004-1\">Yes, because Unser might be .23 miles ahead at different times<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn8004 value=2 id=\"qn8004-2\" \/><label for=\"qn8004-2\">Yes, because Unser is always ahead of Montoya<\/label><\/li> \n<li><input class=\"unind\" type=radio name=qn8004 value=3 id=\"qn8004-3\" \/><label for=\"qn8004-3\">No, because Unser is only .23 miles ahead of Montoya once because two linear graphs only intersect once<\/label><\/li> \n<\/ul>\n<\/div><\/span><\/p>\n<\/div>\n","jsparams":{"8000":{"tip":"Enter text","longtip":"Enter your answer as letters. Examples: A B C, linear, a cat","calcformat":"","qtype":"string"},"8001":{"qtype":"essay"},"8002":{"tip":"Enter an algebraic equation","longtip":"Enter your answer as an equation. Example: y=3x^2+1, 2+x+y=3\n<br\/>Be sure your variables match those in the question","helper":1,"preview":1,"calcformat":"equation","vars":["x","y","t"],"fvars":[],"domain":[[-10,10,false],[-10,10,false],[-10,10,false]],"qtype":"numfunc"},"8003":{"qtype":"essay"},"8004":{"qtype":"choices"},"helps":[]},"answeights":["0.33","0","0.33","0","0.34"],"usedautosave":[],"work":"","errors":[]}],"in_practice":false,"enddate_disp":"Sun 10\/25\/20, 10:00 pm"}
Add error_reporting(0) in your config.php. Warnings and such shouldn't be output to users.
As for the actual cause of the error, it looks like you're running a slightly different version of the code, so the line number isn't helping me find what might be causing it. Being a warning, this isn't a big deal and should just be suppressed in the output.
Perfect. The error suppression fixed the issue with the end-user. Any suggestions for how to track down the cause of the error on my end?
You can still view the error in your PHP error log, and it should give a line number. Just your line numbers don't match my current line numbers.
It's also hard sometimes to tell if the error is being caused by the system code, or by a bug in a question being generated. Sometimes the error log will include a stack trace that will make it easier to track the source.