1. Solve.

x^2+9x+2=0

Enter your answers, as exact values, in the boxes.


2. What is the solution of the equation when solved over the complex numbers?

x^2+24=0


Respuesta :

1. using the quadratic formula you get -9+/-sqrt(9^2-4*(1*2))/2*1

 this simplies to x = -9 +/- sqrt(73)/2

x = -0.22799812 and -8.77200187


2.  complex numbers have the letter i with them

 using the quadratic formula

 you get 0 +/- sqrt(0^2-4*(1*24))/2*1

x = -2i sqrt(6) and 2i sqrt(6)

Answer and explanation:

1) Solve : [tex]x^2+9x+2=0[/tex]

Applying quadratic formula,

[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]

Here, a=1 , b=9, c=2

[tex]x=\frac{-9\pm\sqrt{9^2-4(1)(2)}}{2(1)}[/tex]

[tex]x=\frac{-9\pm\sqrt{81-8}}{2}[/tex]

[tex]x=\frac{-9\pm\sqrt{73}}{2}[/tex]

[tex]x=\frac{-9+\sqrt{73}}{2},\frac{-9-\sqrt{73}}{2}[/tex]

[tex]x=-0.227,-8.772[/tex]

2) Given : [tex]x^2+24=0[/tex]

To find : What is the solution of the equation when solved over the complex numbers?

Solution :

Quadratic equation, [tex]x^2+24=0[/tex]

Subtract 24 both side,

[tex]x^2+24-24=-24[/tex]

[tex]x^2=-24[/tex]

Taking root both side,

[tex]x=\sqrt{-24}[/tex]

[tex]x=\pm 2\sqrt{6}i[/tex]

The solution of the equation is [tex]x=2\sqrt{6}i,-2\sqrt{6}i[/tex]