COS5π/3=要步骤

COS5π/3=要步骤 sin5/3π= ,cos5/3π cos5π等于= 计算cos5分之π+cos5分之2π+cos5分之3π+cos5分之4π 计算cos5分之π+cos5分之2π+cos5分之3π+cos5分之4π sin(-4/3π）+cos5/6π= cos5π/3为什么等于1/2? 求值cosπ/11*cos2π/11*cos3π/11*cos4π/11*cos5π/11求详细过程和重要步骤的原因(1/4*sin8π/11*cos3π/11*cos5π/11)/2sinπ/11=(1/4*sin3π/11*cos3π/11*cos5π/11)/2sinπ/11这一步骤是怎么变过来的 cos5分之π×cos5分之2π 反三角函数求值arccos(cos5π/4)=?arctan(tan4π/3)=?arcsin(sin6)=? 计算cos5分之派+cos5分之2派+cos5分之3派+cos5分之4派 cos5/6π=?sin5/6π=? cos5π/12-根3sin5π/12过程 cos5π/12=sinπ/12 怎么算的? 求值:cos5π/8cosπ/8= 表达虚数式Express the complex number in trigonometric form.3 - 3iA) 3*(cos5π/4 +isin5π/4)B) 3*root of2*(cos7π/4 +isin7π/4)C) 3*(cos7π/4 +isin7π/4)D) 3*root of2*(cos5π/4 +isin5π/4)（root of 2 就是根号2）我的步骤是：3*（1-i） cos5π/3为什么等于1/2不是-1/2?cos5π/3=cos（5π/3-2π）=cos（-π/3）=-cosπ/3=-1/2不是这样的吗 sin4π/3cos5π/6tan(－4π/3)怎么做,求详细过程sin4π/3乘以cos5π/6乘以tan(－4π/3)=？