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How Do You Find the Quotient of a Polynomial?

Published in Polynomial Division 2 mins read

To find the quotient of a polynomial division, you typically use polynomial long division, similar to the long division method used for numbers.

Steps for Polynomial Long Division:

  1. Arrange: Ensure both the dividend (the polynomial being divided) and the divisor (the polynomial you're dividing by) are written in descending order of exponents. Add placeholders (terms with a coefficient of 0) for any missing exponents. For example, if you have x3 + 1 being divided by x + 1, write the dividend as x3 + 0x2 + 0x + 1.

  2. Divide: Divide the first term of the dividend by the first term of the divisor. This will be the first term of the quotient.

  3. Multiply: Multiply the divisor by the term you just found in the quotient.

  4. Subtract: Subtract the result from the corresponding terms in the dividend.

  5. Bring Down: Bring down the next term from the dividend.

  6. Repeat: Repeat steps 2-5 using the new polynomial you created until the degree of the remaining polynomial (the remainder) is less than the degree of the divisor.

  7. Write the Result: The quotient is the polynomial you built in step 2. The remainder (if any) is the polynomial left after the final subtraction. Express the result as:

    Dividend / Divisor = Quotient + Remainder / Divisor

Example:

Let's divide (x2 + 3x + 2) by (x + 1).

x + 2
x + 1 x2 + 3x + 2
x2 + x
------- ---------
2x + 2
2x + 2
------- ---------
0

Explanation:

  • Divide: x2 / x = x (This is the first term of the quotient)
  • Multiply: x * (x + 1) = x2 + x
  • Subtract: (x2 + 3x + 2) - (x2 + x) = 2x + 2
  • Divide: 2x / x = 2 (This is the second term of the quotient)
  • Multiply: 2 * (x + 1) = 2x + 2
  • Subtract: (2x + 2) - (2x + 2) = 0 (Remainder)

Therefore, (x2 + 3x + 2) / (x + 1) = x + 2 + 0/(x+1) = x + 2.

Alternative Methods

  • Synthetic Division: A shorthand method for polynomial division, but it only works when the divisor is of the form (x - a), where a is a constant.

Key Considerations:

  • Be mindful of signs during the subtraction steps.
  • Always ensure polynomials are arranged in descending order of exponents.
  • If a term is missing in the dividend, add a placeholder with a coefficient of 0.

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