Quadratic Equation/Examples/x^2 + 1 = 0

Example of Quadratic Equation
The quadratic equation:
 * $x^2 + 1 = 0$

has no root in the set of real numbers $\R$:


 * $x = \pm i$

where $i = \sqrt {-1}$ is the imaginary unit.

Proof
From the Quadratic Formula: