In which of the following pairs are two numbers reciprocals of each other?I $\sqrt5$ and $\sqrt5$/5II $\sqrt5$ and -$\sqrt5$III 5 and 1/5
A)I only
B)I and II
C)I and III
D)II and III

Question

Quizplus · Accepted Answer

The reciprocal of m is 1/m and the product of two reciprocal numbers is 1. Apply this test for the three pairs:
I $\sqrt5$ x $\sqrt5$/5 = 5/5 = 1
II $\sqrt5$ x -$\sqrt5$ = -5
III 5 x 1/5 = 1
The first and the third pairs are reciprocal pairs.
Key takeaway: The sign $\sqrt{}$ indicates square root of a number. You can multiply and divide square roots just like you would any number. However you can not add or subtracts the same way.

In Which of the Following Pairs Are Two Numbers Reciprocals 5\sqrt55​

In Which of the Following Pairs Are Two Numbers Reciprocals $\sqrt5$