题目

已知tanα=，则等于（ ） A．    B． C．﹣7  D．7 答案：A【考点】同角三角函数基本关系的运用． 【专题】计算题；三角函数的求值． 【分析】原式分子分母除以cosα，利用同角三角函数间基本关系化简，将tanα的值代入计算即可求出值． 【解答】解：∵tanα=﹣， ∴原式===， 故选：A． 【点评】此题考查了同角三角函数基本关系的运用，熟练掌握基本关系 — What do you know about the traffic accident ______ yesterday?    — It was the drunken driver who was ______ for it. A. occurred; to blame                         B. occurring; to blame C. to be occurred; to be blamed                 D. occurring; to be blamed