What is the Maclaurin series for f(x)=cosh(x)=ex+e−x2f(x) = \cosh(x) = \frac{e^x + e^{-x}}{2}f(x)=cosh(x)=2ex+e−x?
∑n=0∞x2n(2n)!\sum_{n=0}^{\infty} \frac{x^{2n}}{(2n)!}∑n=0∞(2n)!x2n
∑n=0∞xnn!\sum_{n=0}^{\infty} \frac{x^n}{n!}∑n=0∞n!xn
∑n=0∞(−1)nx2n(2n)!\sum_{n=0}^{\infty} (-1)^n \frac{x^{2n}}{(2n)!}∑n=0∞(−1)n(2n)!x2n
∑n=0∞x2n+1(2n+1)!\sum_{n=0}^{\infty} \frac{x^{2n+1}}{(2n+1)!}∑n=0∞(2n+1)!x2n+1