化简:√(1-sinα) +√(1sinα)

1个回答

  • √(1-sinα)+√(1+sinα)

    =√(sin^2(α/2)+cos^2(α/2)-2sin(α/2)cos(α/2))

    +√(sin^2(α/2)+cos^2(α/2)+2sin(α/2)cos(α/2))

    =√(sin(α/2)-cos(α/2))2+√(sin(α/2)+cos(α/2))2

    =|sin(α/2)-cos(α/2)|+|sin(α/2)+cos(α/2)|

    当a∈(0,π/2)时,cos(α/2)>sin(α/2)>0

    原式=cos(α/2)-sin(α/2)+cos(α/2)+sin(α/2)=2cos(α/2)

    当α∈[π/2,π)时,0<cos(α/2)≤sin(α/2)

    原式=sin(α/2)-cos(α/2)+sin(α/2)+cos(α/2)=2sin(α/2)