Differential Equations and Linear Algebra (4th Edition)

Published by Pearson
ISBN 10: 0-32196-467-5
ISBN 13: 978-0-32196-467-0

Appendix B - Review of Partial Fractions - Exercises for B - Problems - Page 803: 12

Answer

\[\frac{10}{(x-1)(x^2+9)}=\frac{1}{(x-1)}-\frac{x+1}{x^2+9}\]

Work Step by Step

In this case the general form of the partial fraction decomposition is \[\frac{10}{(x-1)(x^2+9)}=\frac{A}{(x-1)}+\frac{Bx+C}{x^2+9}\;\;\;...(*)\] \[10=A(x^2+9)+(Bx+C)(x-1)\] \[10=A(x^2+9)+(Bx^2-Bx+Cx-C)\] Comparing like coefficients \[A+B=0\;\;\;...(1)\] \[C-B=0\Rightarrow C=B\;\;\;...(2)\] \[9A-C=10\;\;\;...(3)\] Using (2) in (3) \[9A-B=10\;\;\;...(4)\] Add (1) and (4) \[10A=10\Rightarrow A=1\] From (1) \[B=-1\] From (2) \[C=-1\] From (*) \[\frac{10}{(x-1)(x^2+9)}=\frac{1}{(x-1)}+\frac{-1x-1}{x^2+9}\] \[\frac{10}{(x-1)(x^2+9)}=\frac{1}{(x-1)}-\frac{x+1}{x^2+9}\] Hence \[\frac{10}{(x-1)(x^2+9)}=\frac{1}{(x-1)}-\frac{x+1}{x^2+9}.\]
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.