(x3+x2+x+2)÷(x2−1)=

4 min read Jun 17, 2024
(x3+x2+x+2)÷(x2−1)=

Solving the Polynomial Division: (x³ + x² + x + 2) ÷ (x² - 1)

This article will walk through the steps of dividing the polynomial (x³ + x² + x + 2) by (x² - 1). We'll use the long division method to solve this problem.

Understanding Long Division with Polynomials

Long division with polynomials works similarly to long division with numbers. We aim to find a quotient polynomial that, when multiplied by the divisor (x² - 1), gives us the dividend (x³ + x² + x + 2).

Here's the breakdown of the process:

  1. Set up the division:

        _________
    x² - 1 | x³ + x² + x + 2
    
  2. Divide the leading terms:

    • The leading term of the dividend (x³) is divided by the leading term of the divisor (x²). This gives us x.
    • Write this quotient (x) above the dividend.
        x     
        _________
    x² - 1 | x³ + x² + x + 2 
    
  3. Multiply the quotient by the divisor:

    • Multiply the quotient (x) by the divisor (x² - 1). This results in x³ - x.
        x     
        _________
    x² - 1 | x³ + x² + x + 2 
           x³ - x 
    
  4. Subtract the result from the dividend:

    • Subtract the result (x³ - x) from the dividend. Remember to change the signs of the terms you're subtracting.
        x     
        _________
    x² - 1 | x³ + x² + x + 2 
           x³ - x 
           -------
              x² + 2x + 2
    
  5. Bring down the next term:

    • Bring down the next term (+2) from the dividend.
        x     
        _________
    x² - 1 | x³ + x² + x + 2 
           x³ - x 
           -------
              x² + 2x + 2
    
  6. Repeat steps 2-5:

    • Divide the new leading term (x²) by the leading term of the divisor (x²), which gives us 1.
    • Write this quotient (1) next to the first quotient (x) in the answer.
    • Multiply the new quotient (1) by the divisor (x² - 1) to get x² - 1.
    • Subtract this result from the expression below the line.
        x + 1 
        _________
    x² - 1 | x³ + x² + x + 2 
           x³ - x 
           -------
              x² + 2x + 2
              x² - 1
              -------
                 2x + 3
    
  7. Continue until the degree of the remaining polynomial is less than the degree of the divisor.

    • The degree of the remaining polynomial (2x + 3) is 1, which is less than the degree of the divisor (x² - 1).

Final Result

Therefore, the solution to the division (x³ + x² + x + 2) ÷ (x² - 1) is:

(x³ + x² + x + 2) ÷ (x² - 1) = x + 1 + (2x + 3) / (x² - 1)

This means the quotient is x + 1 and the remainder is 2x + 3. The remainder is expressed as a fraction with the divisor as the denominator.

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