Question

Is $5i$ a real number?

Answer 1

Checking if $5i$ is a real number

A real number consists of both rational numbers and irrational numbers. It consists of integers, fractions and decimals.

Any number other than the complex number is a real number.

A complex number is a number of the form $x+iy$ where $x,y$ are real numbers and $i$ is the imaginary part.

In the case of $5i$, there is an imaginary part present. Hence, $5i$ is a complex number and not a real number.

Therefore, $5i$ is not a real number.