已知:sin(θ+3π)=-23,则tan(-5π-θ)•cos(θ-2π)•sin(-3π-θ)tan(7π2+θ)•sin(-4π+θ)•cot(-θ-π2)+2tan(6π-θ)•cos(-π+

题目简介

已知:sin(θ+3π)=-23,则tan(-5π-θ)•cos(θ-2π)•sin(-3π-θ)tan(7π2+θ)•sin(-4π+θ)•cot(-θ-π2)+2tan(6π-θ)•cos(-π+

题目详情

已知:sin(θ+3π)=-
2
3
,则
tan(-5π-θ)•cos(θ-2π)•sin(-3π-θ)
tan(
2
+θ)•sin(-4π+θ)•cot(-θ-
π
2
)
+2tan(6π-θ)•cos(-π+θ)
=______.
题型:填空题难度:中档来源:不详

答案

因为sin(θ+3π)=-class="stub"2
3

∴sinθ=class="stub"2
3

tan(-5π-θ)•cos(θ-2π)•sin(-3π-θ)
tan(class="stub"7π
2
+θ)•sin(-4π+θ)•cot(-θ-class="stub"π
2
)
+2tan(6π-θ)•cos(-π+θ)

=
tan(-θ)•cosθ•sinθ
-cotθ•sinθ•(-tanθ)
+2(-tanθ)•(-cosθ)
=-sinθ+2sinθ
=sinθ=class="stub"2
3

故答案为:class="stub"2
3

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