The square root of minus 1.

The symbol is

But when we square any Real Number we always get a positive, or zero, result. For example:

• 2 × 2 = 4, and

• (-2) × (-2) = 4 also.

So how can we square a number and get a negative result? Just "imagine" that we can, and it turns out that such a number, which may seem impossible, is actually useful and can solve real problems.

The symbol is

**"i"**But when we square any Real Number we always get a positive, or zero, result. For example:

• 2 × 2 = 4, and

• (-2) × (-2) = 4 also.

So how can we square a number and get a negative result? Just "imagine" that we can, and it turns out that such a number, which may seem impossible, is actually useful and can solve real problems.

See: Real Number