Given the inequality:
$$x^{2} + 2 > 0$$
To solve this inequality, we must first solve the corresponding equation:
$$x^{2} + 2 = 0$$
Solve:
This equation is of the form
a*x^2 + b*x + c = 0
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 1$$
$$b = 0$$
$$c = 2$$
, then
D = b^2 - 4 * a * c =
(0)^2 - 4 * (1) * (2) = -8
Because D<0, then the equation
has no real roots,
but complex roots is exists.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = \sqrt{2} i$$
$$x_{2} = - \sqrt{2} i$$
$$x_{1} = \sqrt{2} i$$
$$x_{2} = - \sqrt{2} i$$
Exclude the complex solutions:
This equation has no roots,
this inequality is executed for any x value or has no solutions
check it
subtitute random point x, for example
x0 = 0
$$0^{2} + 2 > 0$$
2 > 0
so the inequality is always executed