化简cos^4x-2sinxcosx-sin^4x

来源:学生作业帮助网 编辑:作业帮 时间:2024/07/17 15:51:17
化简cos^4x-2sinxcosx-sin^4x
x){38 ]̼ B $P_`gC) 8$Y  (+ #TBDCUT…BDBWdjNqAbWКg~

化简cos^4x-2sinxcosx-sin^4x
化简cos^4x-2sinxcosx-sin^4x

化简cos^4x-2sinxcosx-sin^4x
(cosx)^4-2sinxcosx-(sinx)^4
=(cosx)^4-(sinx)^4-2sinxcosx
=[(cosx)^2-(sinx)^2][(cosx)^2+(sinx)^2]-2sinxcosx
=[(cosx)^2-(sinx)^2]-2sinxcosx
=cos2x-sin2x