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求积分(1+sinx)/[sinx*(1+cosx)]dx

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/07/01 12:47:22
求积分(1+sinx)/[sinx*(1+cosx)]dx
∫{(1+sinx)/[sinx(1+cosx)]}dx
=∫{1/[sinx(1+cosx)]}dx+∫[1/(1+cosx)]dx
=∫{sinx/[(six)^2(1+cosx)]}dx+(1/2)∫{[1/[cos(x/2)]^2}dx
=-∫{1/[(1-cosx)(1+cosx)^2]}d(cosx)+∫{1/[cos(x/2)]^2}d(x/2)
=-(1/2)∫{(1-cosx+1+cosx)/[(1-cosx)(1+cosx)^2]}d(cosx)
 +arctan(x/2)
=-(1/2)∫[1/(1+cosx)^2]d(cosx)
 -(1/2)∫{1/[(1-cosx)(1+cosx)]d(cosx)+arctan(x/2)
=(1/2)[1/(1+cosx)]+arctan(x/2)
 -(1/4)∫{(1-cosx+1+cosx)/[(1-cosx)(1+cosx)]}d(cosx)
=1/(2+2cosx)+arctan(x/2)-(1/4)∫[1/(1+cosx)]d(cosx)
 -(1/4)∫[1/(1-cosx)]d(cosx)
=1/(2+2cosx)+arctan(x/2)-(1/4)ln(1+cosx)+(1/4)ln(1-cosx)+C.
再问: 看着眼晕 还是谢谢你 不过∫{1/[cos(x/2)]^2}d(x/2)=∫[sec(x/2)]^2d(x/2)=tan(x/2)+C 这里是你错了还是我错了
再答: 抱歉!是我们都错了。 ∫{(1+sinx)/[sinx(1+cosx)]}dx =∫{1/[sinx(1+cosx)]}dx+∫[1/(1+cosx)]dx =∫{sinx/[(six)^2(1+cosx)]}dx+(1/2)∫{[1/[cos(x/2)]^2}dx =-∫{1/[(1-cosx)(1+cosx)^2]}d(cosx)+∫{1/[cos(x/2)]^2}d(x/2) =-(1/2)∫{(1-cosx+1+cosx)/[(1-cosx)(1+cosx)^2]}d(cosx)  +tan(x/2) =-(1/2)∫[1/(1+cosx)^2]d(cosx)  -(1/2)∫{1/[(1-cosx)(1+cosx)]d(cosx)+tan(x/2) =(1/2)[1/(1+cosx)]+tan(x/2)  -(1/4)∫{(1-cosx+1+cosx)/[(1-cosx)(1+cosx)]}d(cosx) =1/(2+2cosx)+tan(x/2)-(1/4)∫[1/(1+cosx)]d(cosx)  -(1/4)∫[1/(1-cosx)]d(cosx) =1/(2+2cosx)+tan(x/2)-(1/4)ln(1+cosx)+(1/4)ln(1-cosx)+C。