问题
解答题
已知函数f(x)=
(1)求函数f(x)的最小正周期; (2)求使函数f(x)取得最大值的x的集合. |
答案
(1)f(x)=
sin(2x-3
)+1-cos2(x-π 6
)π 12
=2[
sin2(x-3 2
)-π 12
cos2(x-1 2
)]+1π 12
=2sin[2(x-
)-π 12
]+1π 6
=2sin(2x-
)+1π 3
∴T=
=π2π 2
(2)当f(x)取最大值时,sin(2x-
)=1,有2x-π 3
=2kπ+π 3 π 2
即x=kπ+
(k∈Z)5π 12
∴所求x的集合为{x∈R|x=kπ+
,(k∈Z)}.5π 12