(1)∵y=3sin(2x+
),π 4
∴周期T=
=π,2π 2
增区间满足-
+2kπ≤2x+π 2
≤π 4
+2kπ,k∈Z,π 2
解得增区间为[-
+kπ,3π 8
+kπ],k∈Z;π 8
减区间满足
+2kπ≤2x+π 2
≤π 4
+2kπ,k∈Z,3π 2
解得减区间为[
+kπ,π 8
+kπ],k∈Z.5π 8
(2)∵y=3sin(2x+
),π 4
∴y=3sin(2x+
)的值域为[-3,3];π 4
对称轴方程满足2x+
=kπ+π 4
,k∈Z,π 2
解得该函数的对称轴方程为x=
+kπ 2
,k∈Z.π 8