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x^2=8

x^2=8 equation

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Numerical solution:

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The solution

You have entered [src]
 2    
x  = 8
$$x^{2} = 8$$
Detail solution
Move right part of the equation to
left part with negative sign.

The equation is transformed from
$$x^{2} = 8$$
to
$$x^{2} - 8 = 0$$
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
$$a = 1$$
$$b = 0$$
$$c = -8$$
, then
D = b^2 - 4 * a * c = 

(0)^2 - 4 * (1) * (-8) = 32

Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)

x2 = (-b - sqrt(D)) / (2*a)

or
$$x_{1} = 2 \sqrt{2}$$
$$x_{2} = - 2 \sqrt{2}$$
Vieta's Theorem
it is reduced quadratic equation
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 0$$
$$q = \frac{c}{a}$$
$$q = -8$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = 0$$
$$x_{1} x_{2} = -8$$
The graph
Rapid solution [src]
          ___
x1 = -2*\/ 2 
$$x_{1} = - 2 \sqrt{2}$$
         ___
x2 = 2*\/ 2 
$$x_{2} = 2 \sqrt{2}$$
x2 = 2*sqrt(2)
Sum and product of roots [src]
sum
      ___       ___
- 2*\/ 2  + 2*\/ 2 
$$- 2 \sqrt{2} + 2 \sqrt{2}$$
=
0
$$0$$
product
     ___     ___
-2*\/ 2 *2*\/ 2 
$$- 2 \sqrt{2} \cdot 2 \sqrt{2}$$
=
-8
$$-8$$
-8
Numerical answer [src]
x1 = -2.82842712474619
x2 = 2.82842712474619
x2 = 2.82842712474619
The graph
x^2=8 equation