题目内容
实数x,y满足tanx=x,tany=y,且|x|≠|y|,则
-
=______.
| sin(x+y) |
| x+y |
| sin(x-y) |
| x-y |
tanx=
=x
∴sinx=xcosx
同理,siny=ycosy
所以原式=
-
=
-
=
-
=cosxcosy-cosxcosy
=0
故答案为:0
| sinx |
| cosx |
∴sinx=xcosx
同理,siny=ycosy
所以原式=
| sinxcosy+cosxsiny |
| x+y |
| sinxcosy-cosxsiny |
| x-y |
=
| xcosxcosy-ycosxcosy |
| x-y |
| xcosxcosy+ycosxcosy |
| x+y |
=
| cosxcosy(x+y) |
| x+y |
| cosxcosy(x-y) |
| x-y |
=cosxcosy-cosxcosy
=0
故答案为:0
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