Respuesta :

Answer:

The roots of the the given equation are +3i or -3i.

Solution:

Given, [tex]3x^2+27=0[/tex]

First of all compare the given equation with the standard form, i.e [tex]ax^2+bx+c=0[/tex]

On comparing,  

a=3

b=0

c=27

According to the quadratic formula,

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

[tex]b^2-4ac= 0-4\times3\times27=-324[/tex]

As [tex]b^2-4ac[/tex] comes out to be negative, the given equation does not have any real roots,

[tex]\sqrt {b^2-4ac}= \sqrt{(-324)}[/tex]

[tex]\sqrt {b^2-4ac}= \sqrt{(324\times -1)}[/tex]

[tex]\Rightarrow \sqrt{324}\times \sqrt{-1}[/tex]

Root of 324 is 18,

[tex]\Rightarrow 18\times i[/tex] (Because root of -1 is i)

[tex]x=\frac{(-0+-18i)}{2\times3}[/tex]

[tex]x=\frac{\pm18i}{6}[/tex]

[tex]x=\frac{+18}{6} \ or \frac{-18}{6}[/tex]

On dividing 18 and 6 we get,

[tex]\therefore x=+3i \ or -3i[/tex]

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