Next we will show you that 1 = -1:

We start from the following equation that is true: -1 = -1

We turn it into fractions:

If we apply the square root on both sides of the equation we have:

What is equivalent to:

We know where *i* It is the imaginary number And therefore the equation looks like this:

If we now remove the fractions we have the following:

And since we know what and what

We have left that: 1 = -1

Quod erat demonstrandum

#### Solution

The problem is that the roots cannot be distributed when it comes to negative numbers and it is not possible to simplify the root with the square when the number is negative. You will find a more extensive definition on Wikipedia.