Question

The numbers ___ and ___ are their own reciprocals.

• A. 1 and 0
• B. 0 and -1
• C. 1 and 2
• D. 1 and -1

Answer 1

The correct option is D

1 and -1

A number is a reciprocal of itself if the number written as a fraction where numerator is 1 gives the same number.

1's reciprocal is $\frac{1}{1}$ = 1 itself

So is the case for -1 as $\frac{1}{-1}$ = -1 itself

$\therefore$ The numbers -1 and 1 are their own reciprocals.