若sinθ+cosθ=2,则tan(θ+π3)的值是 _ .
问题描述:
若sinθ+cosθ=
,则tan(θ+
2
)的值是 ___ .π 3
答
∵sinθ+cosθ=
,平方可得sin2θ=1,
2
=1,2sinθcosθ
sin2θ+ cos2θ
∴
=1,tanθ=1.2tanθ
tan2θ +1
∴tan(θ+
)=π 3
=tanθ+
3
1-
tanθ
3
=-2-1+
3
1-
3
,
3
故答案为 -2-
.
3