Fails to find the integral of sqrt(a*x)

[derivitaandrew]

These are all as expected:

integral(sqrt(x))        => 2/3 x^(3/2)
integral(sqrt(1 + 2x))   => 1/3*(8x^3 + 12x^2 + 6x + 1)^(1/2)
integral(sqrt(2)sqrt(x)) => 2/3*2^(1/2) x^(3/2)

but there's a problem with the pattern sqrt(a*x):

integral(sqrt(2x))
# Expect 2/3*2^(1/2) x^(3/2) (same as last case above)
Stop: integral: sorry, could not find a solution