求证sin(x+3/1π)-根号3cos(3/2π-x)=2sin(x-3/1π)=0
问题描述:
求证sin(x+3/1π)-根号3cos(3/2π-x)=2sin(x-3/1π)=0
答
对于这个 使用三角函数展开sin(x+y)=sinx *cosy + cos x* siny代入sin(x+3/1π)=sin x cos(3/1π)+cosx sin(3/1π)=(1/2)*sinx+根号3*cosx根号3cos(3/2π-x)=(-根号3)/2 * cos x+(根号3)/2 * sinxsin(x+3/1π)-根号3...