abacus21
Jun 1, 2010, 03:09 PM
Use the Maclaurin series of cos(x) to state the first three non zero terms of the Maclaurin Series for (1-cos x)/x^2
galactus
Jun 1, 2010, 06:43 PM
The series for cos(x) is
\sum_{k=0}^{\infty}(-1)^{k}\frac{x^{2k}}{(2k+1)!}
Just do as it says. Subtract from 1 and then divide that result by x^2.
This eliminates the 1 in the original series for cos(x), switches the signs, and reduces the powers of x in the numerators by a power of 2.
\sum_{k=0}^{\infty}(-1)^{k}\frac{x^{2k}}{(2k+2)!}