第2个回答 2019-07-13
∫ y^2.e^(-2y) dy
=-(1/2)∫ y^2 de^(-2y)
=-(1/2) y^2.e^(-2y) + ∫ ye^(-2y) dy
=-(1/2) y^2.e^(-2y) -(1/2) ∫ y de^(-2y)
=-(1/2) y^2.e^(-2y) -(1/2) ye^(-2y) + (1/2) ∫e^(-2y) dy
=-(1/2) y^2.e^(-2y) -(1/2)ye^(-2y) - (1/4)e^(-2y) + C本回答被提问者和网友采纳