prove that 2 tan inverse {root of a-b / a+b * tan theta /2 } = cos inverse { a cos thetha + b / a +b cos thetha} Share with your friends Share 18 Pooja Khanna answered this Here is the link for the answer to your query: https://www.meritnation.com/ask-answer/question/prove-that-2-tan-1-root-of-a-b-a-b-tn-theta-2-cos-1-ac/inverse-trigonometric-functions/7340871 11 View Full Answer