2014 National Question 12 Single-choice Differentiating 2014_daganji_old 12.(5分)奇函数f(x)的定义域为R,若f(x+2)为偶函数,且f(1)=1,则f(8)+f(9)=( ) A. ﹣2B. ﹣1C. 0D. 1 Answer keyD ☆ SaveCan't do it, show the explanation查看原卷 →