Question 374969
Use x-y format.
{{{y=sqrt(12-x)}}}
Interchange the positions of x and y and solve for the new y.
That new y is the inverse function.
{{{highlight(x)=sqrt(12-highlight(y))}}}
{{{x^2=12-y}}}
{{{y=12-x^2}}}
{{{highlight(f^(-1)(x)=12-x^2)}}}