2010年12月12日SAT数学官方每日一题

　　考试类型：Mathematics > Standard Multiple Choice

　　Read the following SAT test question, then click on a button to select your answer. If , which of the following statements must also be true? . . . A. None B. only C. only D. only E. and

　　正确答案:E 解析: The quantity can be expressed as . If , then and . Since , either or or both. Therefore, statement must be true, but statement , , is not always true. For statement , you can write , and since , it follows that . Therefore, both statements and must be true