Math Problem Statement

To find 𝑓 ( 1 / 2 ) f(1/2) using synthetic division and the Remainder Theorem, we will first perform synthetic division of the polynomial 𝑓 ( π‘₯ )

2 π‘₯ 5 + 5 π‘₯ 4 βˆ’ 4 π‘₯ 2 + 3 π‘₯ βˆ’ 1 f(x)=2x 5 +5x 4 βˆ’4x 2 +3xβˆ’1 by π‘₯ βˆ’ 1 2 xβˆ’ 2 1 ​ .

Step 1: Set up synthetic division.

We will use 1 2 2 1 ​ and the coefficients of 𝑓 ( π‘₯ ) f(x):

Solution

To evaluate f(12)f\left(\frac{1}{2}\right) using synthetic division and the Remainder Theorem, follow these steps:

  1. Set up synthetic division.

    • First, rewrite the polynomial f(x)=2x5+5x4βˆ’4x2+3xβˆ’1f(x) = 2x^5 + 5x^4 - 4x^2 + 3x - 1 and list the coefficients.
    • Since some terms are missing (e.g., x3x^3), include zeros as placeholders.

    The polynomial f(x)f(x) has coefficients: [2,5,0,βˆ’4,3,βˆ’1][2, 5, 0, -4, 3, -1].

  2. Write down the synthetic division setup.

    • We are dividing by xβˆ’12x - \frac{1}{2}, so use 12\frac{1}{2} as the synthetic divisor.
  3. Perform synthetic division.

    • Bring down the first coefficient, 22.
    • Multiply 22 by 12\frac{1}{2} and add to the next coefficient.
    • Repeat this process across all coefficients.

Let's go through each step in the synthetic division process:

Coefficients250-43-1
Multiply11331.51.5βˆ’1.25-1.250.3750.375
Add226633βˆ’2.5-2.51.751.75βˆ’0.625-0.625
  1. Interpret the result.
    • The remainder (last entry) after synthetic division is βˆ’0.625-0.625, which is the value of f(12)f\left(\frac{1}{2}\right) by the Remainder Theorem.

So, f(12)=βˆ’0.625f\left(\frac{1}{2}\right) = -0.625.

Would you like further details on any part of this process?


5 Questions to Explore Further:

  1. How is the Remainder Theorem generally used in evaluating polynomial functions?
  2. Why are placeholders (like the 00 for x3x^3) necessary in synthetic division?
  3. What happens if the divisor is a different form, like x+ax + a, in synthetic division?
  4. Can synthetic division be applied to non-polynomial expressions?
  5. How does synthetic division differ from traditional polynomial long division?

Tip: Always check for missing terms in a polynomial and use zeros as placeholders in synthetic division to maintain accuracy.

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Math Problem Analysis

Mathematical Concepts

Algebra
Polynomials
Synthetic Division
Remainder Theorem

Formulas

Synthetic division process
Remainder Theorem: f(a) = R, where R is the remainder

Theorems

Remainder Theorem

Suitable Grade Level

Grades 10-12