Polynomial Long Division: (6x³ + 10x² + x + 8) ÷ (2x² + 1)
This article explores the process of dividing the polynomial 6x³ + 10x² + x + 8 by the polynomial 2x² + 1 using polynomial long division.
Setting Up the Division
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Organize the Polynomials: Write the dividend (6x³ + 10x² + x + 8) and the divisor (2x² + 1) in a long division format, ensuring both polynomials are in descending order of their exponents. Notice that the dividend has a missing x term, so we can include a placeholder '0x' for clarity.
2x² + 1 | 6x³ + 10x² + x + 8
Performing the Division
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Divide the Leading Terms: Divide the leading term of the dividend (6x³) by the leading term of the divisor (2x²), which gives 3x. Write this term above the line in the quotient.
3x 2x² + 1 | 6x³ + 10x² + x + 8
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Multiply the Quotient by the Divisor: Multiply the term just written in the quotient (3x) by the entire divisor (2x² + 1), which results in 6x³ + 3x. Write this product below the dividend.
3x 2x² + 1 | 6x³ + 10x² + x + 8 6x³ + 3x
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Subtract: Subtract the product (6x³ + 3x) from the corresponding terms of the dividend. Remember that subtracting a term is the same as adding its opposite.
3x 2x² + 1 | 6x³ + 10x² + x + 8 6x³ + 3x ------- 10x² - 2x + 8
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Bring Down the Next Term: Bring down the next term of the dividend (8) to the bottom line.
3x 2x² + 1 | 6x³ + 10x² + x + 8 6x³ + 3x ------- 10x² - 2x + 8
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Repeat Steps 1-4: Repeat the process with the new polynomial (10x² - 2x + 8). Divide the leading term of this polynomial (10x²) by the leading term of the divisor (2x²), which gives 5. Write 5 in the quotient.
3x + 5 2x² + 1 | 6x³ + 10x² + x + 8 6x³ + 3x ------- 10x² - 2x + 8 10x² + 5
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Subtract: Subtract the product (10x² + 5) from the corresponding terms.
3x + 5 2x² + 1 | 6x³ + 10x² + x + 8 6x³ + 3x ------- 10x² - 2x + 8 10x² + 5 ------- -2x + 3
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Final Step: Since the degree of the remaining polynomial (-2x + 3) is less than the degree of the divisor (2x² + 1), we stop here. The remainder is -2x + 3.
The Result
The result of the division can be expressed as follows:
(6x³ + 10x² + x + 8) ÷ (2x² + 1) = 3x + 5 + (-2x + 3)/(2x² + 1)
This means that:
- Quotient: 3x + 5
- Remainder: -2x + 3
Therefore, we have successfully divided the polynomial 6x³ + 10x² + x + 8 by the polynomial 2x² + 1 using long division.