（Ⅰ）试比较f（﹣1）与f（a）的大小；

（Ⅱ）当a≥﹣1时，若函数f（x）的图象和x轴围成一个三角形，则实数a的取值范围．

    Mom and dad are the most important people in your life. They have been looking after you since you were born， you should always love them. You should also get on well with them. But some children don't know how to do this. Here are some ways to help you.

    Spend more time with your parents. Don't spend too much time playing computer games or watching TV. Ask your parents to play with you. Talk or go outside with them.

    Be kind to your parents. You can make them happy with a smile when you come home. You can send your mother a card on Mother's Day or tell your father a joke on his birthday. You can also clean your room by yourself.

    Work hard. If you do your best in your studies， your parents will be proud of you.