根号下(2+2sin(2π-θ)-cos^2(π+θ))可化简为

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根号下(2+2sin(2π-θ)-cos^2(π+θ))可化简为

√[2+2sin(2π-θ)-cos^2(π+θ)]
=√[2-2sinθ-cos^2θ]
=√[2-2sinθ-(1-sin^2θ)]
=√(sin^2θ-2sinθ+1)
=√(sinθ-1)^2
=1-sinθ
朋友,你刚刚采纳的那个没做完,我这个才是对的.因为1>sinθ,所以|sinθ-1|=1-sinθ
而且肯定是先用诱导公式变形后再继续运算,2sin(2π-θ)=-2sinθ,
cos^2(π+θ)=cos^2θ,这样才会越算越简单.好吧,晚安了.

楼主答的真好,学习中~~

=根号下(2+2sinθ-cos^2θ)
=根号下(1+2sinθ-sin^2θ)
=1-sinθ