Let X∼N(0,1)X \sim N(0, 1)X∼N(0,1). Find E[etX]E[e^{tX}]E[etX].
ete^tet
et2e^{t^2}et2
et2/2e^{t^2/2}et2/2
et/2e^{t/2}et/2