Answer :

Answer:

The factors are (x+6),[tex]x-2i\sqrt{2}[/tex] and [tex]x+2i\sqrt{2}[/tex]

Therefore the given polynomial

[tex]x^3+6x^2+8x+48=(x+6)(x-2i\sqrt{2})(x+2i\sqrt{2})[/tex]

Step-by-step explanation:

Given polynomial is [tex]x^3+6x^2+8x+48[/tex]

To factorise the polynomial equate the given polynomial to zero

[tex]x^3+6x^2+8x+48=0[/tex]

By using synthetic division we can find the factors :

[tex]x^3+6x^2+8x+48=0[/tex]

_-6|   1       6     8     48

        0     -6     0    -48

__________________

        1       0      8      0

Therefore (x+6) is a factor

The quadratic equation is [tex]x^2+8=0[/tex]

To solve it we can use [tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]

Here a=1 b=0 and c=8

[tex]x=\frac{-(0)\pm\sqrt{0^2-4(1)(8)}}{2(1)}[/tex]

[tex]=\frac{\pm\sqrt{-32}}{2}[/tex]

[tex]=\frac{\pm\sqrt{32i^2}}{2}[/tex] where [tex]i^2=-1[/tex]

[tex]=\frac{\pm4i\sqrt{2}}{2}[/tex]

[tex]=\pm2i\sqrt{2}[/tex]

[tex]x=\pm2i\sqrt{2}[/tex]

Therefore [tex]x=2i\sqrt{2}[/tex] and [tex]x=-2i\sqrt{2}[/tex]

Therefore the factors are (x+6),[tex]x-2i\sqrt{2}[/tex] and [tex]x+2i\sqrt{2}[/tex]

Therefore the given polynomial

[tex]x^3+6x^2+8x+48=(x+6)(x-2i\sqrt{2})(x+2i\sqrt{2})[/tex]