In which of the following pairs are the two numbers reciprocals of each other?
I. 3 and ~$\frac{1}{3}$~
II.~$\frac{1}{17}$~ and -~$\frac{1}{17}$~
III.~$\sqrt{3}$~and~$\frac{\sqrt{3}}{3}$~
I only
II only
I and II
I and III
II and III
题目分析:
两个数的乘积为 1,则这两个数互为倒数.
I. 3*1/3=1. 互为倒数
II. 1/17*(-1/17)!=1.不互为倒数
III. ~$\sqrt{3}$~ *~$\frac{\sqrt3}{3}$~ =1.互为倒数
综上:答案是 D.
reciprocal 倒数,两个数的乘积为 1,则这两个数互为倒数.
reciprocal 倒数