先积y,后积x,画图观察,0lnx] dx
=∫[1-->e]x*(x-1)dx
=∫[1-->e](x^2-x)dx
=1/3x^3-1/2x^2 [1-->e]
=1/3e^3-1/2e^2-1/3+1/2
=1/3(e^3-1)-1/2(e^2-1)
先积y,后积x,画图观察,0lnx] dx
=∫[1-->e]x*(x-1)dx
=∫[1-->e](x^2-x)dx
=1/3x^3-1/2x^2 [1-->e]
=1/3e^3-1/2e^2-1/3+1/2
=1/3(e^3-1)-1/2(e^2-1)