Math Problem Statement

solve

Use synthetic division to divide x^3 + 8 by x + 2. Write your answer in the form q(x) + r(x)/d(x), where q(x) is the quotient, r(x) is the remainder, and d(x) is the divisor.

Solution

To solve the problem of dividing x3+8x^3 + 8 by x+2x + 2 using synthetic division, let's go step-by-step.

Step 1: Set up for synthetic division.

Synthetic division works when the divisor is in the form xcx - c. Here, we have x+2x + 2, which can be written as x(2)x - (-2). So, c=2c = -2.

We will divide x3+0x2+0x+8x^3 + 0x^2 + 0x + 8 (since there are missing terms for x2x^2 and xx) by x+2x + 2.

The coefficients of x3+0x2+0x+8x^3 + 0x^2 + 0x + 8 are:
[1,0,0,8][1, 0, 0, 8]

Step 2: Perform synthetic division.

  1. Write c=2c = -2 on the left and the coefficients on the right: -2 & 1 & 0 & 0 & 8 \\ \end{array}$$
  2. Bring the first coefficient (1) down: -2 & 1 & 0 & 0 & 8 \\ & & 1 \\ \end{array}$$
  3. Multiply 1 by -2 and write the result under the next coefficient: -2 & 1 & 0 & 0 & 8 \\ & & 1 & -2 \\ \end{array}$$
  4. Add the column: 0+(2)=20 + (-2) = -2: -2 & 1 & 0 & 0 & 8 \\ & & 1 & -2 \\ & & & -2 \\ \end{array}$$
  5. Multiply 2-2 by 2-2 and write the result under the next coefficient: -2 & 1 & 0 & 0 & 8 \\ & & 1 & -2 & 4 \\ \end{array}$$
  6. Add the column: 0+4=40 + 4 = 4: -2 & 1 & 0 & 0 & 8 \\ & & 1 & -2 & 4 \\ & & & & 4 \\ \end{array}$$
  7. Multiply 44 by 2-2 and write the result under the next coefficient: -2 & 1 & 0 & 0 & 8 \\ & & 1 & -2 & 4 & -8 \\ \end{array}$$
  8. Add the column: 8+(8)=08 + (-8) = 0: -2 & 1 & 0 & 0 & 8 \\ & & 1 & -2 & 4 & -8 \\ & & & & & 0 \\ \end{array}$$

Step 3: Interpret the result.

The bottom row gives the coefficients of the quotient and the remainder:

  • The quotient is x22x+4x^2 - 2x + 4.
  • The remainder is 0, so there is no remainder.

Final Answer:

The result of dividing x3+8x^3 + 8 by x+2x + 2 is: q(x)=x22x+4q(x) = x^2 - 2x + 4

In the required form q(x)+r(x)d(x)q(x) + \frac{r(x)}{d(x)}, the answer is simply: x22x+4x^2 - 2x + 4

Would you like any further details on synthetic division or have any questions?

Here are some related questions you may want to explore:

  1. How does synthetic division work with a non-zero remainder?
  2. How would the process differ if dividing by x2x - 2?
  3. Can synthetic division handle polynomials of higher degrees?
  4. What is the difference between synthetic and long division?
  5. How do you interpret results when dividing by a divisor with a leading coefficient other than 1?

Tip: Synthetic division works best when the divisor is a linear binomial of the form xcx - c, and it's a quick alternative to long division for these cases!

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Math Problem Analysis

Mathematical Concepts

Polynomial Division
Synthetic Division

Formulas

Synthetic division setup for dividing polynomials

Theorems

Remainder Theorem

Suitable Grade Level

Grades 10-12