问题
选择题
函数f（x）=x2-2x-2，x∈[-4，4]，那么任意x0∈[-4，4]使f（x0）≤1的概率为（ ）
|
答案
令f（x）=x2-2x-2≤1解得-1≤x≤3，故事件f（x0）≤1对应的测度为4
总的基本事件对应的测度是8
故任意x0∈[-4，4]使f（x0）≤1的概率为1 2
故选D
搜题请搜索小程序“爱下问搜题”
函数f（x）=x2-2x-2，x∈[-4，4]，那么任意x0∈[-4，4]使f（x0）≤1的概率为（ ）
|
令f（x）=x2-2x-2≤1解得-1≤x≤3，故事件f（x0）≤1对应的测度为4
总的基本事件对应的测度是8
故任意x0∈[-4，4]使f（x0）≤1的概率为1 2
故选D
| 完形填空。 | ||||
| There was a woman in Detroit, who has two sons. She was worried about them, especially the younger one, Ben, __1__ he was not doing well in school. Boys in his class made jokes about him because he seemed so __2___. The mother decided that she would, herself, have to get her sons to do better in school. She told them to go to the Detroit Public Library to read a __3___ a week and do a report about it for her. One day, in Ben's __4___, the teacher held up a rock and asked if anyone knew it. Ben put up his hand and the teacher let him ___5__. "Why did Ben raise his hand?" they wondered. He __6__ said anything; what could he possibly want to say? Well, Ben not only _7___ the rock; he said a lot about it. He named other rocks in its group and even knew __8___ the teacher had found it. The teacher and the students were __9__. Ben had learned all this from doing one of his book __10___. Ben later went on to the __11__ of his class. When he finished high school, he went to Yale University and at last became one of the best doctors in the United States. After Ben had grown up, he _12__ something about his mother that he did not know as a _13___. She, herself, had never learned how to __14__. | ||||
|