Give an example of two polynomials

• October 5th 2012, 10:20 AM
Eraser147
Give an example of two polynomials
Give an example of two polynomials of degree 9 whose sum has degree 4. I have no clue where to start with this. I don't know if I am supposed to make the factors cancel out.
• October 5th 2012, 10:44 AM
FernandoRevilla
Re: Give an example of two polynomials
Quote:

Originally Posted by Eraser147
Give an example of two polynomials of degree 9 whose sum has degree 4. I have no clue where to start with this. I don't know if I am supposed to make the factors cancel out.

$p(x)=x^9+x^4,\;q(x)=-x^9+x^4$ . :)
• October 5th 2012, 10:47 AM
Eraser147
Re: Give an example of two polynomials
it was really just that simple?
• October 5th 2012, 10:49 AM
FernandoRevilla
Re: Give an example of two polynomials
Quote:

Originally Posted by Eraser147
it was really just that simple?

Yes, very simple.
• October 5th 2012, 10:51 AM
HallsofIvy
Re: Give an example of two polynomials
That satisfies all the conditions doesn't it? If you want to be more complicated, make up any two 9th degree polynomials such that, when you add, all terms with power greater than 4 cancel but the terms with power 4 do not.

Your misunderstanding may have to do with thinking that factors have to cancel. That won't happen when you are adding polynomials.
• October 5th 2012, 10:54 AM
Eraser147
Re: Give an example of two polynomials
Well, thanks guys.