Inverse Cosine
Inverse functions can be found algebraically by interchanging x and y in the function definition and then making y the subject of the equation.
They can also be found graphically by reflecting the graph of the function in the line y = x. (Some adjustment may be needed to the domain of the original function to ensure that the inverse function is in fact a function.)
To produce the inverse of y = cos (x), follow the instructions below the construction.