Question

in †abc with the usual notations prove that (a-b)2– cos—^2 (c/2) + (a+b)2– sin—^2 (c/2) = c2

Answer 1

We have in a triangle \Delta ABC ,. \cos^2(\frac{C}{2} )+\. LHS=(a-b)^2\cos ^2(\frac{C . Simplifying,. LHS=(a^2+b^2)(1)-