Math Problem Statement

Find the remainder and determine whether the divisor is a factor for each of the given polynomial division problems.

Solution

To solve these problems, we’ll use the Remainder Theorem, which states that the remainder of a polynomial f(x)f(x) divided by xax - a is f(a)f(a). This theorem also helps us determine if the divisor is a factor: if the remainder is zero, the divisor is a factor; if not, it isn’t.

Let's solve each one step-by-step.


Problem 1

Polynomial: p48p3+10p2+2p+4p^4 - 8p^3 + 10p^2 + 2p + 4
Divisor: p2p - 2

  1. Set p=2p = 2 and substitute p=2p = 2 into the polynomial: f(2)=24823+1022+22+4f(2) = 2^4 - 8 \cdot 2^3 + 10 \cdot 2^2 + 2 \cdot 2 + 4
  2. Calculate each term:
    • 24=162^4 = 16
    • 823=64-8 \cdot 2^3 = -64
    • 1022=4010 \cdot 2^2 = 40
    • 22=42 \cdot 2 = 4
  3. Sum these values: f(2)=1664+40+4+4=0f(2) = 16 - 64 + 40 + 4 + 4 = 0
  4. Conclusion: The remainder is 0, so p2p - 2 is a factor of the polynomial.

Problem 2

Polynomial: x5+6x43x222x29x^5 + 6x^4 - 3x^2 - 22x - 29
Divisor: x+6x + 6

  1. Rewrite the divisor as x(6)x - (-6), so set x=6x = -6.
  2. Substitute x=6x = -6 into the polynomial: f(6)=(6)5+6(6)43(6)222(6)29f(-6) = (-6)^5 + 6 \cdot (-6)^4 - 3 \cdot (-6)^2 - 22 \cdot (-6) - 29
  3. Calculate each term:
    • (6)5=7776(-6)^5 = -7776
    • 6(6)4=61296=77766 \cdot (-6)^4 = 6 \cdot 1296 = 7776
    • 3(6)2=336=108-3 \cdot (-6)^2 = -3 \cdot 36 = -108
    • 22(6)=132-22 \cdot (-6) = 132
  4. Sum these values: f(6)=7776+7776108+13229=5f(-6) = -7776 + 7776 - 108 + 132 - 29 = -5
  5. Conclusion: The remainder is -5, so x+6x + 6 is not a factor of the polynomial.

Problem 3

Polynomial: n525n37n237n18n^5 - 25n^3 - 7n^2 - 37n - 18
Divisor: n+5n + 5

  1. Rewrite the divisor as n(5)n - (-5), so set n=5n = -5.
  2. Substitute n=5n = -5 into the polynomial: f(5)=(5)525(5)37(5)237(5)18f(-5) = (-5)^5 - 25 \cdot (-5)^3 - 7 \cdot (-5)^2 - 37 \cdot (-5) - 18
  3. Calculate each term:
    • (5)5=3125(-5)^5 = -3125
    • 25(5)3=25125=3125-25 \cdot (-5)^3 = -25 \cdot -125 = 3125
    • 7(5)2=725=175-7 \cdot (-5)^2 = -7 \cdot 25 = -175
    • 37(5)=185-37 \cdot (-5) = 185
  4. Sum these values: f(5)=3125+3125175+18518=8f(-5) = -3125 + 3125 - 175 + 185 - 18 = -8
  5. Conclusion: The remainder is -8, so n+5n + 5 is not a factor of the polynomial.

Problem 4

Polynomial: n4+10n3+21n2+6n8n^4 + 10n^3 + 21n^2 + 6n - 8
Divisor: n+2n + 2

  1. Rewrite the divisor as n(2)n - (-2), so set n=2n = -2.
  2. Substitute n=2n = -2 into the polynomial: f(2)=(2)4+10(2)3+21(2)2+6(2)8f(-2) = (-2)^4 + 10 \cdot (-2)^3 + 21 \cdot (-2)^2 + 6 \cdot (-2) - 8
  3. Calculate each term:
    • (2)4=16(-2)^4 = 16
    • 10(2)3=108=8010 \cdot (-2)^3 = 10 \cdot -8 = -80
    • 21(2)2=214=8421 \cdot (-2)^2 = 21 \cdot 4 = 84
    • 6(2)=126 \cdot (-2) = -12
  4. Sum these values: f(2)=1680+84128=0f(-2) = 16 - 80 + 84 - 12 - 8 = 0
  5. Conclusion: The remainder is 0, so n+2n + 2 is a factor of the polynomial.

Would you like more details on any of the steps? Here are five questions for further exploration:

  1. How is the Remainder Theorem applied in more complex polynomial division?
  2. What is synthetic division, and how can it simplify calculations here?
  3. Why does a remainder of zero imply that the divisor is a factor of the polynomial?
  4. How can we verify these results using alternative methods?
  5. What are some practical applications of polynomial division in real-world contexts?

Tip: Always double-check calculations in polynomial division, as minor errors can lead to incorrect conclusions about factors and remainders.

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Math Problem Analysis

Mathematical Concepts

Polynomial Division
Remainder Theorem
Factorization

Formulas

Remainder Theorem: The remainder of f(x) divided by x - a is f(a)

Theorems

Remainder Theorem

Suitable Grade Level

Grades 10-12