I'm done with this question..Can anyone help me?

tan^-1(yz/xr) + tan^-1(zx/yr) +tan^-1(xy/zr) = pi/4 Prove that x^2+ y^2+ z^2=r^2

2 answers

Quite an interesting result, new to me.
I see you have a typo.

This problem is discussed here:

http://math.stackexchange.com/questions/364002/prove-that-tan-1-fracyzxr-tan-1-fraczxyr-tan-1-fracxy
Hello, to do this sum there is an easiest formula, tan^-1x + tan^-1y + tan^-1 z = x+ y + z - xyz / 1-xy-yz-zx, use this formula u will surely get the answer