Calculus 8th Edition

Published by Cengage
ISBN 10: 1285740629
ISBN 13: 978-1-28574-062-1

Chapter 4 - Integrals - 4.2 The Definite Integral - 4.2 Exercises - Page 317: 11

Answer

$$ \int_{0}^{2} \frac{x}{x+1} d x, \quad n=5 $$ The Midpoint Rule gives $$ \begin{aligned} \int_{0}^{2} \frac{x}{x+1} d x \approx \sum_{i=1}^{4} f\left(\bar{x}_{i}\right) \Delta x \approx 0.9071 \end{aligned} $$

Work Step by Step

$$ \int_{0}^{2} \frac{x}{x+1} d x, \quad n=5 $$ The width of the subintervals is $$ \Delta x=(2-0) / 5=\frac{2}{5}, $$ so the endpoints are $0 ,\frac{2}{5} ,\frac{4}{5} ,\frac{6}{5}, \frac{8}{5},$ and $2 $ and the midpoints are$ \frac{1}{5 } ,\frac{3}{5 },\frac{5}{5}, \frac{7}{5}$ and $\frac{9}{5}$ The Midpoint Rule gives $$ \begin{aligned} \int_{0}^{2} \frac{x}{x+1} d x \approx \sum_{i=1}^{5} f\left(\bar{x}_{i}\right) \Delta x \\ =\frac{2}{5}\left(\frac{\frac{1}{3}}{\frac{1}{5}+1}+\frac{\frac{3}{5}}{\frac{3}{5}+1}+\frac{\frac{5}{5}}{\frac{5}{4}+1}+\frac{\frac{7}{5}}{\frac{7}{5}+1}+\frac{\frac{9}{8}}{\frac{8}{5}}\right) \\ =\frac{2}{5}\left(\frac{127}{56}\right)=\frac{127}{140} \approx 0.9071 \end{aligned} $$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.