题目

When someone has deeply hurt you, it can be very difficult to let go of your grudge. But forgiveness is possible and it can be surprisingly helpful to your physical and mental health. Indeed, research has shown that people who forgive have more energy, better appetite (胃口) and better sleep. “People who forgive show less anger and more hopefulness,” says Dr. Frederic Luskin, who wrote the book Forgive for Good. “So it can help save on the wear and tear(消耗) on our body and make people feel more energetic.”    So when someone has hurt you, calm down first. Take plenty 设函数f（x）=sin（ωx-π6）-2cos2ω2x+1（ω＞0）．直线y=3与函数y=f（x）图象相邻两交点的距离为π．（Ⅰ）求ω的值；（Ⅱ）在△ABC中，角A、B、C所对的边分别是a、b、c，若点（B2，0）是函数y=f（x）图象的一个对称中心，且b=3，求△ABC周长的取值范围．