14.设X,Y独立同分布,都服从标准正态分布N(0,1),求E[max(X,Y)].

答案1/(√π) 解析E(|ω|)=∫_-a^(+∞)(|x|)1/(√(4π)) otin[-1/4x^2dx]'=2∫_0^(+∞)1/(√(Hx))e^( =∫_0^(+∞)(√(1+π))e^(-y/4)dy=2/(√n)因此 E(1/2)=E[1/2(x+y+1)]=1/2[E(x)]+[15(x-1)+E]=1/(√(10))135☆☆☆