The convergent series S=n=1∑∞n21 is to be approximated numerically.
a. For an integer N≥1, evaluate the improper integral ∫N∞x21dx in simplest form.
b. Let RN=S−n=1∑Nn21. Using the integral you found in part (a), determine the smallest integer N for which RN<0.05. Show your reasoning clearly.
c. Compute n=1∑Nn21 for the N obtained in part (b). State an interval of length 0.05 that is guaranteed to contain S. Explain why your interval is valid.