Polynomial Remainders: Find the Remainder and Value of a | Homework Equations"

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SUMMARY

The discussion focuses on finding the remainder of the polynomial P(x) = 2x^4 - 7x^3 + ax^2 + 3x - 9 when divided by 2x - 1, and determining the value of 'a' given that the remainder when divided by x + 2 is 17. The user correctly substitutes x = 1/2 into the polynomial, yielding P(1/2) = (a - 33)/4. Additionally, they recognize the need to substitute x = -2 to establish a second equation, P(-2) = 17, to solve for 'a'. This approach effectively utilizes the Remainder Theorem.

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Homework Statement


a) Find the remainder when [tex]P(x)=2x^4-7x^3+ax^2+3x-9[/tex] is divided by [tex]2x-1[/tex]

b) If the remainder, when [tex]P(x)[/tex] is divided by [tex]x+2[/tex], is 17, find the value of a.

Homework Equations


If a polynomial [tex]P(x)[/tex] is divided by [tex](x-a)[/tex], the resultant is [tex](x-a)Qx+R(x)[/tex]

The Attempt at a Solution


For a) I substituted [tex]x=\frac{1}{2}[/tex] into the equation and resulted with [tex]P(\frac{1}{2})=\frac{a-33}{4}[/tex]

For b) I'm unsure what to do with the fact that I now have [tex]P(\frac{1}{2})=\frac{a-33}{4}[/tex] and [tex]P(-2)=17[/tex].

A nudge in the right direction would be greatly appreciated :smile:
 
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P(-2) you will get another equation ^^
except from P(-2)=17,
however you are on the right track
 
Oh wait I sub [tex]P(-2)[/tex] into the equation

I really am that bad at polynomials that I keep missing these simple things!
 

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