Fully Factorise HELP! (1 Viewer)

[Bostick]

x^6-7x^3-8

 

[hscishard]

Didn't work

 

[Bostick]

Didn't work

It's in my textbook. The answer is:

No idea how to get that :S

 

[hscishard]

No I'm saying the question doesn't appear

 

[Bostick]

No I'm saying the question doesn't appear

whoops sorry, fixed it now.

 

[hscishard]

Easy as you notice a pattern.

Let u=x^3

u^2 -7u -8

(u-8)(u+1)
=(x^3-8)(x^3+1)
=(x-2)(x^2+2x+4)(x+1)(x^2-x+1)

 

[Bostick]

Thanks get it now

 

[Entrant]

its just substitution...
your having your HSC's next year?
what unit maths are you doing Bostick?