Question 312493
Use x,y function notation.
{{{ y=sqrt(3x-7) }}}

Interchange the position of x and y and solve for y.
{{{highlight(x)=sqrt(3*highlight(y)-7)}}}
{{{x^2=3y-7}}}
{{{x^2+7=3y}}}
{{{y=(x^2+7)/3}}}
This new y is the inverse function,
{{{f^(-1)(x)=(x^2+7)/3}}}