Let f(x) = x^3 + 5 and g(x) = 3x.
(a) Find g(f(-1))
(b) FInd $f^{-1}(x)$.
a)
f(-1) = (-1)^3 + 5 = 4
So g ( f(-1) ) = g (4) = 3(4) = 12
b) f-1(x)
y = x^3 + 5
y - 5 = x^3 take the cube root
∛ ( y - 5) = x "swap" x and y
∛ ( x - 5 ) = y = f-1(x) = the inverse
