tanx=6,1/2sin^2x+1/3cos^2x=?
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tanx=6,1/2sin^2x+1/3cos^2x=?
![tanx=6,1/2sin^2x+1/3cos^2x=?](/uploads/image/z/18826840-64-0.jpg?t=tanx%3D6%2C1%2F2sin%5E2x%2B1%2F3cos%5E2x%3D%3F)
1/2sin^2x+1/3cos^2x
=1/3(sin^2x+cos^2x)+1/6sin^2x
=1/3+1/6sin^2x
因为tanx=6=sinx/cosx
所以两边平方得sin^2x=36cos^2x
又sin^2x+cos^2x=1
所以sin^2x=36/37
所以1/3+1/6sin^2x
=1/3+(1/6)*(36/37)
=37/111+18/111
=55/111
懂了么
有什么不懂的可以问我
=1/3(sin^2x+cos^2x)+1/6sin^2x
=1/3+1/6sin^2x
因为tanx=6=sinx/cosx
所以两边平方得sin^2x=36cos^2x
又sin^2x+cos^2x=1
所以sin^2x=36/37
所以1/3+1/6sin^2x
=1/3+(1/6)*(36/37)
=37/111+18/111
=55/111
懂了么
有什么不懂的可以问我
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