Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 10 - Section 10.7 - Partial Fractions - 10.7 Exercises - Page 750: 43

Answer

$x^2+\frac{3}{x-2}-\frac{x+1}{x^2+1}$

Work Step by Step

Step 1. Use long division (see page 269), the original rational polynomial becomes $x^2+\frac{2x^2+x+5}{x^3-2x^2+x-2}$ Step 2. Factor the denominator as: $x^2(x-2)+(x-2)=(x-2)(x^2+1)$, and assume the end results as: $x^2+\frac{A}{x-2}+\frac{Bx+C}{x^2+1}$ Step 3. Combine the rational functions above as: $\frac{A(x^2+1)+(Bx+C)(x-2)}{(x-2)(x^2+1)}=\frac{(A+B)x^2+(-2B+C)x+(A-2C))}{(x-2)(x^2+1)}$ Step 4. Compare the above result with the rational part in step 1 to set up the following system of equations: \begin{cases} A+B=2 \\ -2B+C=1\\A-2C=5 \end{cases} Step 5. Use substitution to solve the above equations and get $A=3, B=-1,C=-1$ Step 6. Write the final results as: $x^2+\frac{3}{x-2}-\frac{x+1}{x^2+1}$
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.