2016 Beijing Question 5 Single-choice Differentiating 2016_北京 Paper 5.(5 分)已知 x,y∈R,且 x>y>0,则( ) A. $\frac{1}{x}-\frac{1}{y}>0$B. $\sin x - \sin y > 0$C. $(\frac{1}{2})^x - (\frac{1}{2})^y < 0$D. $\ln x + \ln y > 0$ Answer keyC ☆ SaveCan't do it, show the explanation查看原卷 →