Am I missing something here? Thanks for any help! SN
This could be a bug. For now, you can use
FullSimplify instead of
f = -z*Sqrt[-((-1 + z)*z)] g = Sqrt[-((-1 + z)*z^3)] Simplify[f + g, Assumptions -> 0 <= z <= 1]
FullSimplify[f + g, Assumptions -> 0 <= z <= 1] (* 0 *)
And please post plain text code next time. Hard to copy all this from an image and could make mistake.