一个美术生
Vx=π∫
=π∫<1,e>[(lnx)^2]dx
=π[x(lnx)^2]|<1,e>-2π∫<1,e>(lnx)dx
=πe-2π(xlnx|<1,e>-∫<1,e>dx)
=πe-2π[e-(e-1)]
=(2+e)π.
Vy=2π∫
=2π∫<1,e>[x(lnx)]dx
=π[(x^2)(lnx)]|<1,e>-π∫<1,e>xdx
=πe^2-π(x^2)/2|<1,e>
=π[(e^2)-1]/2.
Vx=π∫
=π∫<1,e>[(lnx)^2]dx
=π[x(lnx)^2]|<1,e>-2π∫<1,e>(lnx)dx
=πe-2π(xlnx|<1,e>-∫<1,e>dx)
=πe-2π[e-(e-1)]
=(2+e)π.
Vy=2π∫
=2π∫<1,e>[x(lnx)]dx
=π[(x^2)(lnx)]|<1,e>-π∫<1,e>xdx
=πe^2-π(x^2)/2|<1,e>
=π[(e^2)-1]/2.