65001/AbMath

Possible derivative bug

65001 opened this issue · 2 comments

65001 commented

Describe the bug
The derivative( (x^2 - x)/e^(1/(2x)), x) may be producing an incorrect function as an output.

Expected behavior
(e^(-1/(2x))(4x^2 - x - 1))/(2x)

65001 commented

Before : (((x*(x-1))*((e^(-1/(2*x)))*((((2*x)*0)--2)/((2*x)^2))))+((e^(-1/(2*x)))*((x*1)+((x-1)*1))))

SIMPLIFICATIONS:
Multiplication Swap
Multiplication Swap
Dual Node Multiplication.
Multiplication by one simplification.
Multiplication by one simplification.
Multiplication by one simplification.
Multiplication by one simplification.
Multiplication by one simplification.

Division -> Multiplication and exponentiation.
Dual Node Multiplication.
Multiplication by one simplification.
Multiplication by zero simplification.

Subtraction by zero. Case 2.

After: (((x*(x-1))*((e^(-1*x))*((-2*-1)*(x^2))))+((e^(-1*(x^-1)))*(x+(x-1))))

65001 commented

Subtraction by zero. Case 2. had a bug where the sign would be dropped.
Dual Node Multiplication. had a bug where the if it was applied it could incorrectly apply.