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:
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Set up the division:
_________ x² - 1 | x³ + x² + x + 2
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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
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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
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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
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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
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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
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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.