题目

—Excuse me. Did you notice whether the No.108 bus had gone by?        —Not          I’ve been standing here.        A．as     B．when C．since D．while 答案：D（本题满分12分）函数对任意实数都有,（Ⅰ）分别求的值；（Ⅱ）猜想 的表达式，并用数学归纳法证明你的结论．