- CarieVinne
-
2sinx·cox
=sinx·cosx+cosx·sinx
=sin(x+x)
=sin2x
sinαcosβ+cosαsinβ=sin(α+β)
- 慧慧
-
sin2x=sin(x+x)=sinxcosx+cosxsinx=2sinxcosx
- meira
-
8??(220-68)?4??60 =2??(220-68)??60 =120??52 =6240
2sinx·cox
=sinx·cosx+cosx·sinx
=sin(x+x)
=sin2x
sinαcosβ+cosαsinβ=sin(α+β)
sin2x=sin(x+x)=sinxcosx+cosxsinx=2sinxcosx
8??(220-68)?4??60 =2??(220-68)??60 =120??52 =6240