Processing math: 100%

計算過程(証明)

+(xμ)2f(x)dx+f(x)dx=+(xμ)2f(x)dx=+x2f(x)dx2μ+xf(x)dx+μ2+f(x)dx=+x22πσ2exp[(xμ)22σ2]dx2μ2μ2=(μ2+σ2)μ2=σ2