题目

Where do the woman and her husband usually eat? A . At home. B . In the office. C . At the restaurant. 答案：C方程x2+2x-1=0的根可看出是函数y=x+2与y=的图象交点的横坐标，用此方法可推断方程x3+x-1=0的实根x所在范围为A.-B.0C.D.1