已知sinx=根号5/5,则sin^4x-cos^4x的值()
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已知sinx=根号5/5,则sin^4x-cos^4x的值()已知sinx=根号5/5,则sin^4x-cos^4x的值()已知sinx=根号5/5,则sin^4x-cos^4x的值()sin^4x-
已知sinx=根号5/5,则sin^4x-cos^4x的值()
已知sinx=根号5/5,则sin^4x-cos^4x的值()
已知sinx=根号5/5,则sin^4x-cos^4x的值()
sin^4x-cos^4x
=(sin²x+cos²x)(sin²x-cos²x)
=sin²x-cos²x
=2sin²x-1
=2×(√5/5)²-1
=2/5-1
=-3/5
1/5