赞 独行者麦田 幼苗
共回答了17个问题采纳率：88.2% 举报
sin^2xtanx+cos^2x/tanx+2sinxcosx-(1+cosx/sinxcosx)
=sin^3x/cosx+cos^3x/sinx+2sinxcosx-(1+cosx/sinxcosx)
=sin^4x.cos^4x/sinxcosx+2sinxcosx-(1+cosx/sinxcosx)
=(sin^4x+cos^4x+2sin^2xcos^2x)/sinxcosx-(1+cosx/sinxcosx)
=(sin^2x+cos^2x)^2/sinxcosx-(1+cosx/sinxcosx)
=1/sinxcosx-(1+cosx/sinxcosx)
=-cosx/sinxcosx=-1/sinx=-cscx
=sin^3x/cosx+cos^3x/sinx+2sinxcosx-(1+cosx/sinxcosx)
=sin^4x.cos^4x/sinxcosx+2sinxcosx-(1+cosx/sinxcosx)
=(sin^4x+cos^4x+2sin^2xcos^2x)/sinxcosx-(1+cosx/sinxcosx)
=(sin^2x+cos^2x)^2/sinxcosx-(1+cosx/sinxcosx)
=1/sinxcosx-(1+cosx/sinxcosx)
=-cosx/sinxcosx=-1/sinx=-cscx
1年前
5
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你能帮帮他们吗