Answer to: Simplify the following. cos(frac{pi}{2} -x)tan x . A. sec x B. sin^2x C. tan x D. csc x By signing up, you'll get thousands...
首先你要熟记sin,cos和tan在四个象限的符号.另外三个csc,sec和cot分别是上面三个的倒数,所以符号相同然后就是诱导公式以下分别说sin和csc12象限是+,34是-利用诱导公式sin(π-x)=sinxsinA=3/5,知道了锐角,则另一个代... 解析看不懂?免费查看同类题视频解析查看解答 更多答案(3) ...