求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8!急救急救

2个回答

  • cosπ/8=cos[(π/4)/2]

    =√[1+cos(π/4)]/2

    =√[1+(√2/2)]/2

    =(1/2)√(2+√2)

    cos(π/16)=cos[(π/6)/2]

    =√[1+cos(π/8)]/2

    =√{1+√[(2+√2)/4]}/2

    =√{[4+√(2+√2)]/8}

    cos(π/32)=cos[(π/16)/2]

    =√[1+cos(π/16)]/2

    =√{1+√[4+√(2+√2)]/8}/2

    =(1/4)√{16+√[4+√(2+√2)}

    sin(π/64)=sin[(π/32)/2]

    =√[1-cos(π/32)]/2

    =√{1-(1/4)√{16+√[4+√(2+√2)}}/2

    =√{4-{16+√[4+√(2+√2)}}/8