若3SinX=CosX,则Cos2X+Sin2X等于?

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若3SinX=CosX,则Cos2X+Sin2X等于?若3SinX=CosX,则Cos2X+Sin2X等于?若3SinX=CosX,则Cos2X+Sin2X等于?sin^2x+cos^2x=1sin^

若3SinX=CosX,则Cos2X+Sin2X等于?
若3SinX=CosX,则Cos2X+Sin2X等于?

若3SinX=CosX,则Cos2X+Sin2X等于?
sin^2x+cos^2x=1
sin^2x+9sin^2x=1
sin^2x=1/10
Cos2X+Sin2X
=cos^2x-sin^2x+2sinxcosx
=9sin^2x-sin^2x+6sin^2x
=14sin^2x
=7/5

若f(sinx)=3-cos2x,则f(cosx)=? 若3SinX=CosX,则Cos2X+Sin2X等于? 若f(cosX)=3-cos2X,则f(sinX) 如果f(sinx)=3-cos2x,则f(cos2x)等于多少?题目是cos2x,不是cosx 若f(cosx)=cos2x,则f(sinx)=? 若f(sinx)=2-cos2x,则f(cosx)等于? 设f(sinx)=3-cos2x,则f(cosx)=? f(sinx)=3-cos2x 则f(cosx)=? f(sinx)=3-cos2x,则f(cosx)=?（详解 f(sinx)=3-cos2x,则f（cosx）= f（sinx)=3-cos2x则f(cosx)等于什么 f（sinx)=3-cos2x则f(cosx)等于什么 cos2x+cosx=0,则sin2x+sinx 为什么cos2x=cosx*cosx-sinx*sinx 若f(sinx)=3-cos2x,则f(cosx)=3+cos2x这是怎么算出来哒? 若x属于（o,pai）且sinx+cosx=-1/3,则cos2x= 若f(cosx)=3-cos2x,则f(sinx)=?说明为什么! 若x∈（0,π）,且sinx+cosx=-1/3,则cos2x=?