Chapter 4, Problem 7P

Use forward and backward difference approximations of $O\left(h\right)$ and a centered difference approximation of $O\left(h^2\right)$ to estimate the first derivative of the function examined in Prob. 4.5. Evaluate the derivative at $x=2$ using a step size of $h=0.2$. Compare your results with the true value of the derivative. Interpret your results on the basis of the remainder term of the Taylor series expansion.