The function f f\,f is defined such that
f(x)=5x−8 f(x) = 5x - 8 f(x)=5x−8Find f−1(x)f^{-1}(x)f−1(x)
The function g g\,g is defined such that g(x)=kx2g(x) = kx^2g(x)=kx2 where k k\,k is a constant. Given that fg(2)=52fg(2) = 52fg(2)=52, work out the value of kkk.