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x^2+3*x+5=0

x^2+3*x+5=0 equation

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Numerical solution:

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The solution

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 2              
x  + 3*x + 5 = 0
$$\left(x^{2} + 3 x\right) + 5 = 0$$
Detail solution
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
$$a = 1$$
$$b = 3$$
$$c = 5$$
, then
D = b^2 - 4 * a * c = 

(3)^2 - 4 * (1) * (5) = -11

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
$$x_{1} = - \frac{3}{2} + \frac{\sqrt{11} i}{2}$$
$$x_{2} = - \frac{3}{2} - \frac{\sqrt{11} i}{2}$$
Vieta's Theorem
it is reduced quadratic equation
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 3$$
$$q = \frac{c}{a}$$
$$q = 5$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = -3$$
$$x_{1} x_{2} = 5$$
The graph
Sum and product of roots [src]
sum
          ____             ____
  3   I*\/ 11      3   I*\/ 11 
- - - -------- + - - + --------
  2      2         2      2    
$$\left(- \frac{3}{2} - \frac{\sqrt{11} i}{2}\right) + \left(- \frac{3}{2} + \frac{\sqrt{11} i}{2}\right)$$
=
-3
$$-3$$
product
/          ____\ /          ____\
|  3   I*\/ 11 | |  3   I*\/ 11 |
|- - - --------|*|- - + --------|
\  2      2    / \  2      2    /
$$\left(- \frac{3}{2} - \frac{\sqrt{11} i}{2}\right) \left(- \frac{3}{2} + \frac{\sqrt{11} i}{2}\right)$$
=
5
$$5$$
5
Rapid solution [src]
               ____
       3   I*\/ 11 
x1 = - - - --------
       2      2    
$$x_{1} = - \frac{3}{2} - \frac{\sqrt{11} i}{2}$$
               ____
       3   I*\/ 11 
x2 = - - + --------
       2      2    
$$x_{2} = - \frac{3}{2} + \frac{\sqrt{11} i}{2}$$
x2 = -3/2 + sqrt(11)*i/2
Numerical answer [src]
x1 = -1.5 + 1.6583123951777*i
x2 = -1.5 - 1.6583123951777*i
x2 = -1.5 - 1.6583123951777*i
The graph
x^2+3*x+5=0 equation