sinxcosx/sinx+cosx的积分为:∫(sinxcosx)/(sinx+cosx)dx=(1/2)(-cosx+sinx)-[1/(2√2)]ln|csc(x+π/4)-cot(x+π/4)|+C,C为积分常数。
解答过程如下:
∫(sinxcosx)/(sinx+cosx)dx
=(1/2)∫(2sinxcosx)/(sinx+cosx)dx
=(1/2)∫[(1+2sinxcosx)-1]/(sinx+cosx)dx
=(1/2)∫(sin²x+2sinxcosx+cos²x)/(sinx+cosx)dx-(1/2)∫dx/(sinx+cosx)
=(1/2)∫(sinx+cosx)²/(sinx+cosx)dx-(1/2)∫dx/[√2sin(x+π/4)]
=(1/2)∫(sinx+cosx)dx-[1/(2√2)]∫csc(x+π/4)dx
=(1/2)(-cosx+sinx)-[1/(2√2)]ln|csc(x+π/4)-cot(x+π/4)|+C
积分基本公式:
1、∫0dx=c
2、∫x^udx=(x^u+1)/(u+1)+c
3、∫1/xdx=ln|x|+c
4、∫a^xdx=(a^x)/lna+c
5、∫e^xdx=e^x+c
6、∫sinxdx=-cosx+c
7、∫cosxdx=sinx+c
8、∫1/(cosx)^2dx=tanx+c
9、∫1/(sinx)^2dx=-cotx+c
时间: 2024-12-04 07:35:01