化简sinA+sin(A+2/3π)+cos(A+5/6π)
问题描述:
化简sinA+sin(A+2/3π)+cos(A+5/6π)
RT
答
sinA+sin(A+2/3π)+cos(A+5/6π)
=sina+sinacos2/3pai+sin2/3paicosa+cosacos5/6pai-sinasin5/6pai
=sina-1/2sina+根号3/2cosa-根号3/2cosa-1/2sina
=0