Let
f(x) = x^2 - 4 if x < 7
f(x) = x + 13 if x >= 7
What is f(f(f(17)))?
f(17) = 17 + 30 = 47
f (f(17)) = f (47) = 47 + 13 = 60
f (f ( f (17) ) ) = f (60) = 60 + 13 = 73
