1, period 6π, amplitude 2, initial phase π/3, symmetry axis -2π/3+3kπ, no symmetry center.

2，y=2√2sin(πx/8+π/4)

The maximum value becomes 2√2 times, the period becomes 8/π times, and then it is shifted to the left by 2 units.

3, the minimum positive period is 6, y=√2sin(πx/3-π/6).

Maximum √2/2, minimum -√2.