1. The problem statement, all variables and given/known data Sketch y = cos-1(2x) and y = sin-1(3x) 2. Relevant equations 3. The attempt at a solution This is my attempt cos-1(2x) = y, which means cos y = 2x produce a table with y from (-pi/2 to pi/2) What I want to confirm is the 2x. I need do 1/2 x instead of 2x when we calculate the x? And 1/3x for the other problem?