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