Mister Exam

x^2+2 inequation

A inequation with variable

The solution

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 2        
x  + 2 > 0
$$x^{2} + 2 > 0$$
x^2 + 2 > 0
Detail solution
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
Solving inequality on a graph
Rapid solution
This inequality holds true always