Differentiate Inverse Cosine - arccos(x) - d/dx [ cos^-1(x) ]

In this video, we work through the steps to find the derivative of the inverse cosine function. First we begin with the Pythagorean identity cos^2(y) + sin^2(y) = 1, then rearranging, we get: cos^2(y) = 1 - sin^2(y). Then taking the square root, we get... cos(y) = sqrt(1 - sin^2(x)) which looks rather like a trigonometric substitution in reverse. Thanks for watching. Please give me a "thumbs up" if you have found this video helpful. Please ask me a maths question by commenting below and I will try to help you in future videos. I would really appreciate any small donation which will help me to help more math students of the world. Please donate here: https://paypal.me/MasterWu Follow me on Twitter! twitter.com/MasterWuMath