1. The problem statement, all variables and given/known data I understand that y = sin -1 x. However, why is it that when one writes x = sin y, one leaves out the -1 2. Relevant equations 3. The attempt at a solution I know that when you invert a trig function, the dependent variable essentially switches from y to x and the independent variable switches from x to y. However, why do you leave out the -1 when you write the inverse sin as x = sin y ?