# find a power series representation for the function

• April 18th 2009, 11:30 PM
twilightstr
find a power series representation for the function
f(x)= x^2/(1-2x)^2 without using maclaurin series
• April 18th 2009, 11:40 PM
CaptainBlack
Quote:

Originally Posted by twilightstr
f(x)= x^2/(1-2x)^2 without using maclaurin series

$f(x)= x^2/(1-2x)^2$

use the binomial expansion of $(1-2x)^{-2}$

CB
• April 19th 2009, 01:13 PM
twilightstr
i still don't know how to solve the problem.
• April 19th 2009, 06:31 PM
CaptainBlack
Quote:

Originally Posted by twilightstr
i still don't know how to solve the problem.

Have you done the binomial expansion? You will find it on Wikipedia, and the relevant paer of the article is reproduced in the attachment. (Use x=1 y=2x r=2 in the formula to get the required expansion)

CB