Evaluate ∑n=0∞(−1)nπ2n4n(2n)!\sum_{n=0}^{\infty} \frac{(-1)^n \pi^{2n}}{4^n (2n)!}∑n=0∞4n(2n)!(−1)nπ2n.
22\frac{\sqrt{2}}{2}22
000
111
−1-1−1