06-23-2014, 05:53 AM
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#9
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the Mathemagician~
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Join Date: Nov 2005
Location: Quebec City
Age: 34
Posts: 1,320
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Re: [Math] Summation Help
Quote:
Originally Posted by SKG_Scintill
You know what, why make another thread about a single question.
This is completely unrelated to the OP, but it's just another math question.
I have no idea how to do this, and sadly, neither does my teacher ![Neutral](images/smiley/Neutral.gif)
I don't know all the technical math in english, so bear with me...
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Define at the given polynomial f(x) and the given number "a" a polynomial g(x) and a number "b" in such a way that f(x) = (x - a)g(x) + b
f(x) = 2x^2 + 3, a = 1
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This is how far I get:
2x^2 + 3 = (x - 1)g(x) + b
...After that I just get entangled in the quadratic formula.
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2x^2 + 3 = (x - 1)g(x) + b
2x^2 + 3 - b = (x - 1)g(x)
Since 2x^2 + 3 - b is a second degree polynomial and (x - 1) is a first degree polynomial, g(x) will be a first degree polynomial in the form of cx + d.
(cx + d)(x - 1) = 2x^2 + 3 - b
cx^2 - cx + dx - d = 2x^2 + 3 - b
So c = 2. That leaves:
2x^2 - 2x + dx - d = 2x^2 + 3 - b
(d - 2)x - d = 3 - b
So d = 2. That leaves:
(2 - 2)x - 2 = 3 - b
-2 = 3 - b
b = 5
So g(x) = 2x + 2 and b = 5.
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