cos2θ=√2/3,则cos^4-sin^4的值为

问题描述:

cos2θ=√2/3,则cos^4-sin^4的值为
cos2θ=(√2)/3,则cos^4 θ-sin^4 θ的值为________.
1个回答 分类:数学 2014-10-16

问题解答:

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cos^4 θ-sin^4 θ=[(cosθ)^2+(sinθ)^2][(cosθ)^2-(sinθ)^2]=1*cos2θ=(√2)/3
 
 
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