问题
解答题
若tan(π+x)=2,求: (1)
(2)
|
答案
tan(π+x)=2,tanx=2,
(1)
=4sinx-2cosx 5cosx+3sinx
=4tanx-2 5+3tanx
=4×2-2 5+3×2
;5 7
(2)
=sinxcosx 1+cos2x
=tanx 2+tan2x
=2 2+2×2
.1 3
若tan(π+x)=2,求: (1)
(2)
|
tan(π+x)=2,tanx=2,
(1)
=4sinx-2cosx 5cosx+3sinx
=4tanx-2 5+3tanx
=4×2-2 5+3×2
;5 7
(2)
=sinxcosx 1+cos2x
=tanx 2+tan2x
=2 2+2×2
.1 3