# Complex number definition explained with examples

Learn and know the complex number definition. In types of numbers, complex number is one of them which we are going to study in class 11. In 10th class we will study up to real numbers.

Do you have any idea that why complex numbers are being introduced? Studying up to real numbers is not sufficient to solve some kind of problems. For example, ${ y }^{ 2 }$ + 1 = 0, for this quadratic equation actually there are no real roots. So can we say that the given quadratic equation cannot be solved? Yes we can solve it by using complex numbers. So to solve such kind of problems studying complex numbers is very useful. Now we will know what exactly a complex number is and also its definition.

## Complex number definition as follows:

A number which is in the form of a + ib is a complex number. Here “a”, “b” are real numbers. It has two parts. One is real part and second one is imaginary part. In a + ib, “a” is called as the “real part” and “b” is called as the “imaginary part”.

Examples:

5 + 2i, 7 – 9i, 13 + 2i,…………………..

In the example, 5 + 2i, “5” is called real part and “2” is called imaginary part. I hope complex number definition is clear.