题目

设曲线，在曲线上一点处的切线记为，则切线与曲线的公共点个数为A. B. C. D. 答案：【答案】C【解析】通过导数的几何意义求得切线方程；再将切线方程与曲线方程联立，求解出根的个数，从而得到公共点个数. 斜率方程为：，即由得：即：，，曲线与的公共点个数为：个本题正确选项：The teacher was ____when he heard the____news.A．excited excitedB．exciting excitingC．excited excitingD．exciting excited