∫∫e^(-y^2)dxdy
=∫(0,1)dy∫(0,y)e^(-y^2)dx
=∫(0,1)ye^(-y^2)dy
=(-1/2)∫(0,1)e^(-y^2)d(-y^2)
=(-1/2)e^(-y^2)|(0,1)
=(-1/2)(1/e-1)
=(1/2)(1-1/e)
这样可以么?题目是Y2不是-y2