(secx)的^(1/3)的积分如何求啊?

2个回答

  • 令(cosx)^(1/3)=t,则:cosx=t^3,∴-sinxdx=3t^2dt,∴dx=[-3t^2/√(1-t^2)]dt.

    ∴原式=∫(1/t)[-3t^2/√(1-t^2)]dt.

    =-3∫[t/√(1-t^2)]dt

    =-(3/2)∫[1/√(1-t^2)]d(t^2)

    =(3/2)∫[1/√(1-t^2)]d(1-t^2)

    =3∫d[√(1-t^2)]

    =3√(1-t^2)+C

    =3√[1-(cosx)^(2/3)]+C