Question

The reciprocal of $-1$ is
A. $1$
B. $-1$
C. $0$
D. Not defined

Answer 1

Hint: Here we have been given a number and we have to find the reciprocal of it. Firstly as we know reciprocal means interchanging the numerator and denominator so we will use this concept to get our answer. We will divide $1$ by the number given as it is the easiest way to find the reciprocal and get our desired answer.

Complete step-by-step solution:
The number is given as follows:
$-1$……$\left( 1 \right)$
We have to find the reciprocal of the above number.
As we know that for any number $n$ its reciprocal is calculated or defined as $\dfrac{1}{n}$ using this formula on equation (1) we get the below value,
$\Rightarrow \dfrac{1}{-1}$
Now rewriting it properly we get,
$\Rightarrow -1$
The reciprocal of $-1$ is $-1$
Hence correct option is (B).

Note: The number given to us is a rational number which is negative in nature. Real numbers consist of both rational as well as irrational numbers. Rational numbers are those numbers that can be expressed in the form $\dfrac{p}{q}$ where $q\ne 0$ . The decimal expansion of a rational number is either terminating, that is, it ends at one point or is repeating, which means the same pattern after the decimal point is repeated. Irrational numbers are those numbers that can’t be expressed as the $\dfrac{p}{q}$ form. Reciprocal is simply the inverse of a number and when we multiply the number by its reciprocal we get the answer as $1$ which is the reason it is also known as multiplicative inverse. In the question we got the reciprocal of $-1$ as $-1$ and the product of the two values is $1$ as the negative sign will get cancelled out.