已知sin(π+θ)=1/3,则cosθ=?tanθ=?
2个回答
答:
sin(π+θ)=1/3
-sinθ=1/3
sinθ=-1/3
结合sin²θ+cos²θ=1解得:
cosθ=±2√2/3
所以:tanθ=±1/(2√2)
所以:
cosθ=±2√2/3
tanθ=±√2/4
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