use term by term differentiation to find the power series for f(x) = 2x/(1 - x^2)^2 centered at a = 0. you…

use term by term differentiation to find the power series for f(x) = 2x/(1 - x^2)^2 centered at a = 0. you may need to manipulate your given series first before differentiating. the power series representation for f(x) is sum(n = 0 to infinity) sqrt(2) x^n help (formulas) (hint: a power series must have all nonnegative integers as the exponents for the variable, so you may need to reindex the power series you find after differentiating.)
Answer
Explanation:
Step1: Recall geometric - series formula
The geometric series $\frac{1}{1 - t}=\sum_{n = 0}^{\infty}t^{n}$, for $|t|\lt1$. Let $t=x^{2}$, then $\frac{1}{1 - x^{2}}=\sum_{n = 0}^{\infty}(x^{2})^{n}=\sum_{n = 0}^{\infty}x^{2n}$, for $|x|\lt1$.
Step2: Differentiate $\frac{1}{1 - x^{2}}$
Differentiate both sides of $\frac{1}{1 - x^{2}}=\sum_{n = 0}^{\infty}x^{2n}$ with respect to $x$. Using the power - rule for differentiation $(x^{m})^\prime=mx^{m - 1}$, the derivative of the left - hand side: $(\frac{1}{1 - x^{2}})^\prime=\frac{2x}{(1 - x^{2})^{2}}$. The derivative of the right - hand side: $(\sum_{n = 0}^{\infty}x^{2n})^\prime=\sum_{n = 1}^{\infty}2nx^{2n - 1}$.
Answer:
$\sum_{n = 1}^{\infty}2nx^{2n - 1}$