Respuesta :

Answer:

The fundamental theorem of algebra guarantees that a polynomial equation has the same number of complex roots as its degree.

Step-by-step explanation:

The fundamental theorem of algebra guarantees that a polynomial equation has the same number of complex roots as its degree.

We have to find the roots of this given equation.

If a quadratic equation is of the form [tex]ax^{2}+bx +c=0[/tex]

Its roots are [tex]\frac{-b+\sqrt{b^{2}-4ac } }{2a}[/tex] and [tex]\frac{-b-\sqrt{b^{2}-4ac } }{2a}[/tex]

Here the given equation is [tex]2x^{2}-4x-1[/tex] = 0

a = 2

b = -4

c = -1

If the roots are [tex]x_{1} and x_{2}[/tex], then

[tex]x_{1}[/tex] = [tex]\frac{-2+\sqrt{(-4)^{2}-4\times 2\times (-1)}}{2\times 2}[/tex]

                       = [tex]\frac{4 +\sqrt{24}}{4}[/tex]

                       = [tex]\frac{2+\sqrt{6} }{2}[/tex]

[tex]x_{2}[/tex] = [tex]\frac{-2-\sqrt{(-4)^{2}-4\times 2\times (-1)}}{2\times 2}[/tex]

                        = [tex]\frac{4 +\sqrt{8}}{4}[/tex]

                        = [tex]\frac{2-\sqrt{6} }{2}[/tex]

These are the two roots of the equation.