[MOVED] given f(x)=x+1 and g(x)=x-1 find (f+g)(x)

unregistered

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Sep 29, 2006
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37
Given
fxts6.jpg
and
gxvp4.jpg
find
fgor9.jpg


The answer in the book shows:

totalct9.jpg


What I don't understand is why is it x^2 - x + 1 and not x^2 - 1 + x?

I'm just trying to understand.
 
Re: given f(x)=x+1 and g(x)=x-1 find (f+g)(x)

unregistered said:
Given
fxts6.jpg
and
gxvp4.jpg
find
fgor9.jpg


The answer in the book shows:

totalct9.jpg


first of all, the functions you posted as f(x) and g(x) do not work out to the desired result ... sure you posted the correct f(x) and g(x)? If f(x) = x+1 and g(x) = x-1, then (f+g)(x) = (x+1) + (x-1) = 2x

What I don't understand is why is it x^2 - x + 1 and not x^2 - 1 + x?

This can easily be explained ... it's just standard notation for a polynomial. x<sup>2</sup> - x + 1 = x<sup>2</sup> - 1 + x (you "see" that fact, correct?) ... normally, polynomials are written in what is called "decreasing" order of degree (degree is the value of the exponent) ... highest first, then the next lower exponent, right on down to the constant.

x<sup>2</sup> - x - 1 is really x<sup>2</sup> - x<sup>1</sup> - 1x<sup>0</sup> ... see how the exponents decrease in order?
 
Awe man, sorry about the goof, I posted an old link.

To answer your question, yes, I do see that fact now thanks to you. Your breakdown was extremely helpful, I forgot all of my math stuff from last year.

Thank-you so so much.
 
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