高一数学,谢谢
化成乘积的形式cos2x-cos3x+2sin(3x/2)sin(x/2)
参考答案:原式=2sin(5x/2)sin(x/2)+2sin(3x/2)sin(x/2)
=2sin(x/2)[sin(5x/2)+sin(3x/2)]
=2sin(x/2)*2sin2x*cos(x/2)
=2sin(x/2)cos(x/2)*2sin2x
=2sinx*sin2x
化成乘积的形式cos2x-cos3x+2sin(3x/2)sin(x/2)
参考答案:原式=2sin(5x/2)sin(x/2)+2sin(3x/2)sin(x/2)
=2sin(x/2)[sin(5x/2)+sin(3x/2)]
=2sin(x/2)*2sin2x*cos(x/2)
=2sin(x/2)cos(x/2)*2sin2x
=2sinx*sin2x