cos(3分之5π)是等于2分之一吗?
问题描述:
cos(3分之5π)是等于2分之一吗?
答
cos(3分之5π)=cosπcos2π/3-sinπsin2π/3=-cos2π/3=cosπ/3=1/2
cos(3分之5π)是等于2分之一吗?
cos(3分之5π)=cosπcos2π/3-sinπsin2π/3=-cos2π/3=cosπ/3=1/2