题目

已知一次函数y=ax+b的图象上有两点A、B，它们的横坐标分别是3，－1，若二次函数y=x2的图象经过A、B两点．（1）请求出一次函数的表达式；（2）设二次函数的顶点为C，求△ABC的面积． 答案：【答案】（1）；（2）2．【解析】试题分析：（1）将A、B的横坐标代入抛物线的解析式中，即可求得A、B的坐标，然后将它们代入直线的解析式中，可得方程组，解方程组即可求得a、b的值，从而得一次函数的表达式；（2）抛物线y=x2的顶点是原点O，设直线AB与x轴的交点为D，先根据直线AB的解析式求出DEnglish words don't stay the same. People need new words for new ideas and new inventions. Different words come into use, or older words are used in a new way.English can change by borrowing words from other languages. For example, the word "tomato" was borrowed from Mexico and "tea" came from China. New words are formed by putting two words together sometimes. "Countryside" and "earthquake" are made up of two parts. Sometimes new words are shorter forms of older words. As we know, the word "photo" was made from "photograph" by cutting off the end of the longer word. "Plane" was made by cutting off the front part of "airplane". The names of people and products(产品) can become new words, too. Our "sandwich" was named after a man called Sandwich and "sellotape"(透明胶带) was a name given by the company that first made the product.1.New English words are needed because _______.A. people use old words in a new way B. people need a new way to explain thingsC. the old words are not enough D. new ideas and new inventions appear all the time2.Which of the following words was taken to England from another country?A. Plane. B. Sandwich. C. Tomato. D. Countryside.3.Which of the following words came from China?A. Tea. B. Earthquake. C. Airplane. D. Sellotape.4.How many ways of developing English words does the passage tell us?A. Three. B. Four. C. Five. D. Six. 1.D 2.C 3.A 4.B 【解析】本文介绍了英语的发展变化以及新单词的形成方式。重点介绍了英语中四种构词方法。 1.根据“People need new words for new ideas and new inventions.”可知，人们需要新的英语是因为新的观念和发明。故答案选D。 2.根据“The word ‘tomato’ was borrow...