Square
Every complex number is a square, because
where r is the modulus of the complex number.
Explanation
Take a complex number a + bi. The number is called r. It applies
so and
We now calculate
For b ≥ 0 this gives
Example 1
To calculate the square root of the imaginary unit we substitute a = 0 and b = 1 in the formula
From r2 = a2 + b2 follows r = 1 and you get
We take the square root on both sides