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#1 2008-11-29 01:00:59
- GemmaJ1988
- Member
- Registered: 2008-10-08
- Posts: 39
factorise
hey can anyone factorise the following equation:
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#2 2008-11-29 01:04:33
- x.gurl.x
- Member
- Registered: 2008-11-29
- Posts: 1
Re: factorise
Um i'm not s sure.....
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#3 2008-11-29 01:10:30
- Daniel123
- Member
- Registered: 2007-05-23
- Posts: 663
Re: factorise
First of all, factor -1 out:
-(x^3 + 3x + 4)
Now it should be fairy easy to spot that - 1 is a root and so, by the factor theorem, (x+1) is a factor.
-(x+1)(Ax^2 + Bx + C)
From here, you could use long division to find the values of A, B and C, or you could mutliply out and equate coeffients.
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#4 2008-11-29 02:17:51
- GemmaJ1988
- Member
- Registered: 2008-10-08
- Posts: 39
Re: factorise
i've factorised it to get:
is it possible to factorise again?
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#5 2008-11-29 03:06:05
- Daniel123
- Member
- Registered: 2007-05-23
- Posts: 663
Re: factorise
You should have a minus on the outside as well.
Assuming what you have done is correct (you can try it by plugging a few values in), then no, that won't factorise nicely.
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#6 2009-04-12 12:07:14
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: factorise
Hi;
The factors of (x^2-x+4) are complex so that is the best you can do.
bobbym
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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