∫sin2xcos3xdx等于多少

请详细解答!谢谢!
2025-06-24 01:05:14
推荐回答(2个)
回答1:

为  -6/5*(cosx)^5+4/3*(cosx)^3+C

具体过程看图,不懂可以问我~~~

回答2:

先利用积化和差公式:
sin(A)cos(B) = (1/2)[sin(A+B) + sin(A-B)]
∴sin(2x)cos(3x) = (1/2)[sin(2x+3x) + sin(2x-3x)]
= (1/2)[sin5x + sin(-x)]
= (1/2)(sin5x - sinx)

∴∫ sin(2x)cos(3x) dx
= (1/2)∫ sin(5x) dx - (1/2)∫ sinx dx
= (1/2)(1/5)∫ sin(5x) d(5x) - (1/2)∫ sinx dx
= (1/10)(-cos(5x)] + (1/2)cosx + C
= (1/10)[5cosx - cos(5x)] + C