Factorise p(x) as a product of linear factors

[hostergaard]

Homework Statement

http://img33.imageshack.us/img33/1231/lobgave.th.jpg

Homework Equations

The Attempt at a Solution

It's the solution, but i have a feeling that there is a more correct way of doing it. At least i need a way to write it so it is mathematical...
http://img36.imageshack.us/img36/20/opgave2.th.jpg

 

[jbunniii]

Homework Statement

http://img33.imageshack.us/img33/1231/lobgave.th.jpg

Homework Equations

The Attempt at a Solution

It's the solution, but i have a feeling that there is a more correct way of doing it. At least i need a way to write it so it is mathematical...
http://img36.imageshack.us/img36/20/opgave2.th.jpg

Can you start by stating the rational root theorem, and what it says about the possible rational roots of the polynomial?

 

[hostergaard]

Can you start by stating the rational root theorem, and what it says about the possible rational roots of the polynomial?

ok! i will try that.

 

[Random Variable]

After you find one root, I would use synthetic division to find the others.

But I guess it this case you really don't have to.

 

[hostergaard]

Here is it finished, could somebody prof-read it and comment? tell if there's some improvements to be done. ;-)
http://img33.imageshack.us/img33/72/opgave3.th.jpg

 

[Mark44]

The scan of your work is illegible. It appears that you did your work on graph paper, and possibly in pencil, making what you wrote very difficult to read.

 

[larstuff]

Here is it finished, could somebody prof-read it and comment? tell if there's some improvements to be done. ;-)
http://img33.imageshack.us/img33/72/opgave3.th.jpg

Guesswork is a good thing in mathematics, but guesswork often need some kind of reasoning. Drawing a graph by hand / on computer is not guesswork in this case. You should come up with a more sophisticated way of showing what your guesswork builds on.

One way to go by, is to look at the last number in the polynom, and factorize that number, finding numbers that constitute 56. You would then get some of the roots you have come up with doing your "guesswork". After that, do polynom division. Or two.