Mister Exam

Other calculators


x^2-3*x+1=0

x^2-3*x+1=0 equation

The teacher will be very surprised to see your correct solution 😉

v

Numerical solution:

Do search numerical solution at [, ]

The solution

You have entered [src]
 2              
x  - 3*x + 1 = 0
$$\left(x^{2} - 3 x\right) + 1 = 0$$
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
$$a = 1$$
$$b = -3$$
$$c = 1$$
, then
D = b^2 - 4 * a * c = 

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

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

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

or
$$x_{1} = \frac{\sqrt{5}}{2} + \frac{3}{2}$$
$$x_{2} = \frac{3}{2} - \frac{\sqrt{5}}{2}$$
Vieta's Theorem
it is reduced quadratic equation
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = -3$$
$$q = \frac{c}{a}$$
$$q = 1$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = 3$$
$$x_{1} x_{2} = 1$$
The graph
Rapid solution [src]
           ___
     3   \/ 5 
x1 = - - -----
     2     2  
$$x_{1} = \frac{3}{2} - \frac{\sqrt{5}}{2}$$
           ___
     3   \/ 5 
x2 = - + -----
     2     2  
$$x_{2} = \frac{\sqrt{5}}{2} + \frac{3}{2}$$
x2 = sqrt(5)/2 + 3/2
Sum and product of roots [src]
sum
      ___         ___
3   \/ 5    3   \/ 5 
- - ----- + - + -----
2     2     2     2  
$$\left(\frac{3}{2} - \frac{\sqrt{5}}{2}\right) + \left(\frac{\sqrt{5}}{2} + \frac{3}{2}\right)$$
=
3
$$3$$
product
/      ___\ /      ___\
|3   \/ 5 | |3   \/ 5 |
|- - -----|*|- + -----|
\2     2  / \2     2  /
$$\left(\frac{3}{2} - \frac{\sqrt{5}}{2}\right) \left(\frac{\sqrt{5}}{2} + \frac{3}{2}\right)$$
=
1
$$1$$
1
Numerical answer [src]
x1 = 2.61803398874989
x2 = 0.381966011250105
x2 = 0.381966011250105
The graph
x^2-3*x+1=0 equation