∫80∫23√ayf(x,y)dxdy=∫80[∫20Θ(x−3√ay)f(x,y)dx]dy=∫20[∫80Θ(x3−y)f(x,y)dy]dx=∫20[∫x30f(x,y)dy]dx. where Θ is the Heaviside step function.
確定! 回上一頁