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1/x^2-3/x-4=0

1/x^2-3/x-4=0 equation

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Numerical solution:

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The solution

You have entered [src]
1    3        
-- - - - 4 = 0
 2   x        
x             
$$\left(\frac{1}{x^{2}} - \frac{3}{x}\right) - 4 = 0$$
Detail solution
Given the equation:
$$\left(\frac{1}{x^{2}} - \frac{3}{x}\right) - 4 = 0$$
Multiply the equation sides by the denominators:
x^2
we get:
$$x^{2} \left(\left(\frac{1}{x^{2}} - \frac{3}{x}\right) - 4\right) = 0$$
$$- 4 x^{2} - 3 x + 1 = 0$$
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
$$a = -4$$
$$b = -3$$
$$c = 1$$
, then
D = b^2 - 4 * a * c = 

(-3)^2 - 4 * (-4) * (1) = 25

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

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

or
$$x_{1} = -1$$
$$x_{2} = \frac{1}{4}$$
The graph
Sum and product of roots [src]
sum
-1 + 1/4
$$-1 + \frac{1}{4}$$
=
-3/4
$$- \frac{3}{4}$$
product
-1 
---
 4 
$$- \frac{1}{4}$$
=
-1/4
$$- \frac{1}{4}$$
-1/4
Rapid solution [src]
x1 = -1
$$x_{1} = -1$$
x2 = 1/4
$$x_{2} = \frac{1}{4}$$
x2 = 1/4
Numerical answer [src]
x1 = -1.0
x2 = 0.25
x2 = 0.25
The graph
1/x^2-3/x-4=0 equation