cos(3π)/2的值,怎么算的,

问题描述:

cos(3π)/2的值,怎么算的,

cos(3π)/2=cos(2π+π)/2 是求三角函数值的一半 =cosπ/2 =-1/2cos(3π/2)=cos(2π-π/2) 是求一半的三角函数值 =cos(π/2)...