# How do you write the equation cosy=x in the form of an inverse function?

${\cos}^{-} 1 x = y$
This simply means that $\cos y = x$.
An example is $\cos {60}^{\circ} = \frac{1}{2}$.
${\cos}^{-} 1 \left(\frac{1}{2}\right) = {60}^{\circ}$.