The functions fff and ggg are defined by
f(x)=3+4lnx,x>0 f(x) = 3 + 4\ln x, \quad x > 0 f(x)=3+4lnx,x>0 g(x)=8x−42x+1,x>12 g(x) = \frac{8x - 4}{2x + 1}, \quad x > \frac{1}{2} g(x)=2x+18x−4,x>21Find f−1(15)f^{-1}(15)f−1(15).
Use differentiation to prove that ggg is an increasing function.
Find g−1(x)g^{-1}(x)g−1(x).
Find the range of the composite function fgfgfg.