(sinX)3次方的原函数是多少?

问题描述:

(sinX)3次方的原函数是多少?

∫(sinx)^3dx
=-∫(sinx)^2d(cosx)
=-∫[1-(cosx)^2]dcosx
=-[cosx-1/3(cosx)^3]+C
=-cosx+1/3(cosx)^3+C

sinx ^3 = sinx(1-cosx ^2)
∫sinx ^3 dx = ∫(1-cosx ^2)d(cosx)
= -cosx + (1/3) cosx ^3 + C

sin³x=sin²x*sinx
=(1-cos²x)sinx
原式=∫(1-cos²x)sinxdx
=∫(cos²x-1)dcosx
=cos³x/3-cosx+C

ARCSIN 3次根号下X