求 ∫ [(x^3)/(x^2-1)^(1/2)]dx,

来源:学生作业帮助网 编辑:作业帮 时间:2024/12/03 00:32:53
求 ∫ [(x^3)/(x^2-1)^(1/2)]dx,
x @_L׭"P2DYF+]vʵDZ;_E9߹ubΗ[r6&b!rә=Ϯ2d0]a)EHFŁ/n0ej]t)Ap0|WK֢aMl ˶ֽR k( UKuu.ŽŪt`5ef2}Au

求 ∫ [(x^3)/(x^2-1)^(1/2)]dx,
求 ∫ [(x^3)/(x^2-1)^(1/2)]dx,

求 ∫ [(x^3)/(x^2-1)^(1/2)]dx,
设u=(x^2-1)^(1/2),则
x^2=u^2+1
dx^2=d(u^2+1)=2udu
∫[(x^3)/(x^2-1)^(1/2)]dx=∫[(x^2)/[2(x^2-1)^(1/2)]]dx^2
=∫[(u^2+1)/(2u)]*2udu
=∫(u^2+1)du
=u^3/3+u
=u(u^2+3)/3
=(x^2-1)^(1/2)(x^2+2)/3

(2x-1)dx刚好就是d(x^2-x+3)
所以结果就是ln(x^2-x+3)