Let X∼Poisson(λ)X \sim \text{Poisson}(\lambda)X∼Poisson(λ). Evaluate E[cos(πX)]E[\cos(\pi X)]E[cos(πX)].
e−2λe^{-2\lambda}e−2λ
e−λe^{-\lambda}e−λ
cos(πλ)\cos(\pi \lambda)cos(πλ)
000