函数y=cos(π/3-x/2)的单调递减区间是?

问题描述:

函数y=cos(π/3-x/2)的单调递减区间是?

?= COS(π/3-x/2)Y = COS(x/2-π/3)


的COS(x/2-π/3)寻求降间隔
x/2-π/3所属2kππ+2Kπ

x属于2π/ 3 +2Kπ8π/ 3 +2Kπ]

=COS(X/2-π/3)
(X/2-π/3 )位于【2Kπ ,2Kπ+π】
解出即可

y=cos(π/3-x/2)就是y=cos(x/2-π/3)
就是求cos(x/2-π/3)的递减区间
x/2-π/3 属于[2kπ,π+2kπ]
所以x属于[2π/3+2kπ,8π/3+2kπ]