题目

已知tan＝，tan＝，则tan(α＋β)＝________． 答案：考点：两角和的正切公式及运用. 【易错点晴】本题考查的是三角变换中的两角和的正切公式.解答本题的关键是能否看出之间的关系,这是解答这类问题的突破口和切入点.只要能看出这个关系然后直接运用两角和的正切公式求解就能简捷巧妙获解.将一个角看成两个角的和与差是三角变换的精髓之所在,也Sometimes known as “The Big Apple” or “the City That Never Sleeps”, New York is both the most populous city in the USA and a leading center of business, commerce, finance and media. The city is often referred to as “New York City”, in order to distinguish it from the state it is in. The city is part of a large metropolitan（大都市的）area, and the combined city population exceeds 18.7 million.New York City is made up of five boroughs（行政区）and hence another nickname of the city is “The Five Boroughs”. The five boroughs are: The Bronx, Brooklyn, Manhattan, Queens and Staten Island.There are many famous buildings and sights in New York, especially in Manhattan. These include the Empire State Building, the Flatiron Building and the United Nations Building. When you visit New York, make sure you see Central Park, Times Square, Chinatown, Little Italy and of course the Statue of Liberty. Additionally, there are many wonderful museums in New York, some truly excellent shops, some of the world’s best theaters in the Broadway area, and the neighborhoods of Greenwich Village and SoHo which are well-known for the artists who reside there.Getting around New York City is simple—the city’s subway network is one of the most comprehensive in the world, connecting all parts of Manhattan in rapid time.However, the best way to see New York is undoubtedly on foot. Central Park is an ideal place to start a walking tour of New York City—843 acres of shining ponds and lush greenery attract locals and tourists. And apart from offering breathtaking scenery, it is a centre for recreation. Visitors can listen to music groups, watch performers, walk along the trails and even take a romantic ride in a horse carriage.【1】What is the purpose of this passage?A. To explain why New York is called “The Big Apple”.B. To tell people how to visit New York.C. To tell people the history and scenery of New York.D. To introduce the city—New York briefly.【2】From the passage, we learn that ________.A. New York has some of the world’s best theaters in the Broadway areaB. New York State is often called “The Five Boroughs”C. all the famous buildings and sights in New York are in ManhattanD. the writer advise people to see New York City by subway【3】The underlined word “it” in the last paragraph refers to ________.A. New York State B. New York City C. Times Square D. Central Park【4】According to the passage, you can do all the following things in Central Park EXCEPT ________.A. enjoy the beautiful scenery B. watch great performanceC. go for a swim D. take a ride on a horse carriage