For the following exercises, solve the initial value
problem.
499. $f'(x) = x^{-3}$, $f(1) = 1$
500. $f'(x) = \sqrt{x} + x^2$, $f(0) = 2$
501. $f'(x) = cosx + sec^2(x)$, $f(\frac{\pi}{4}) = 2 + \frac{\sqrt{2}}{2}$
502. $f'(x) = x^3 - 8x^2 + 16x + 1$, $f(0) = 0$