sin7°cos37°-sin83°sin37°的值是多少?3Q
问题描述：
sin7°cos37°-sin83°sin37°的值是多少?3Q
答
=cos83°cos37°-sin83°sin37° =cos（83+37） =cos120° =-1/2
sin7°cos37°-sin83°sin37°的值是多少?3Q
=cos83°cos37°-sin83°sin37° =cos（83+37） =cos120° =-1/2