Imaginary Number i

How to use the imaginary number i to simiplify the square root of a negative number: definition, 1 example, and its solution.

Definition

Definition

i = √-1

The number inside the square root sign
cannot be (-).
So i = √-1 is not a real number.

This is why
i is called the imaginary number.

Example

Example

Solution

The minus sign inside the square root means i.

So √-36 = √36i.

36 = 62

Cancel the square root and the square.

Then √62i = 6i.

So 6i is the answer.