Simplification of arctan2(f1,f2) expressions.

asked 2021-07-09 16:35:33 +0100

AlanTStafford gravatar image

updated 2021-07-09 17:09:23 +0100

Why doesn't arctan2(sqrt(a^2 + r^2)*sin(phi)*sin(th), sqrt(a^2 + r^2)*cos(phi)*sin(th)) simplify to phi or at least arctan2(sin(phi),cos(phi))?

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Why should it ?

Emmanuel Charpentier gravatar imageEmmanuel Charpentier ( 2021-07-11 09:01:53 +0100 )edit

I was working out transformations between coordinate systems. As a test I transformed and then untransformed so there should be no change. However I get this term which won't simplify back to phi.

AlanTStafford gravatar imageAlanTStafford ( 2021-07-11 11:38:02 +0100 )edit