Which of the following is equivalent to ∑n=0∞x2nn!\sum_{n=0}^{\infty} \frac{x^{2n}}{n!}∑n=0∞n!x2n?
exe^xex
ex2e^{x^2}ex2
cos(x)\cos(x)cos(x)
cosh(x)\cosh(x)cosh(x)