‘³½ΚΜΜ³½p`fΚi»ΜPWXj
4sinxsin2xTncos2(n-1)Ώ={-cos3x+cos(2n-3)x+cos(2n-1)x-cos(4n-1)x}
4sinxsin2xTnsin2(n-1)Ώ={sin3x+sin(2n-3)x+sin(2n-1)x-sin(4n-1)x}
4sinxsin2x°Tncos2(n-1)Ώ={-°cos3x+°cos(2n-3)x+°cos(2n-1)x-°cos(4n-1)x}
4sinxsin2x°Tnsin2(n-1)Ώ={°sin3x+°sin(2n-3)x+°sin(2n-1)x-°sin(4n-1)x}
{-°cos3x+°cos(2n-3)x+°cos(2n-1)x-°cos(4n-1)x}^2+{°sin3x+°sin(2n-3)x+°sin(2n-1)x-°sin(4n-1)x}^2
d^2={(°Tncos2(n-1)Ώ)^2+(°Tnsin2(n-1)Ώ)}^2/(°Tn)^2
d^2={(4sinxsin2x°Tncos2(n-1)Ώ)^2+(4sinxsin2x°Tnsin2(n-1)Ώ)}^2/(4sinxsin2x°Tn)^2
4sinΏsin2Ώ°TnEsinΏ=°sinrxsin(r+1)x={(N)sin2x-sin2Nx}=(n+1)sin2Ώ
4sinΏsin2Ώ°Tncos2(n-1)ΏEsinΏ=-(n+1)cos3xsinx
4sinΏsin2Ώ°Tnsin2(n-1)ΏEsinΏ=(n+1)sins3xsinx
XX=-cos3xsinx/sin2x
YY=sin3xsinx/sin2x
XX^2+YY^2=(sinx/sin2x)^2=1/(2cosx)^2
d^2¨1/2