Long Division With Polynomials - The Easy Way!

The Organic Chemistry Tutor
7 Apr 201712:11
EducationalLearning
32 Likes 10 Comments

TLDRThis instructional video offers a step-by-step guide on dividing polynomials using long division. It begins with a simple example, dividing \(x^2 + 5x + 6\) by \(x + 2\), and progresses to more complex cases, such as dividing \(2x^3 + 8x^2 - 6x + 10\) by \(x - 2\) and \(6x^4 - 9x^2 + 18\) by \(x - 3\). The video demonstrates the process of dividing, multiplying, and subtracting to find the quotient and remainder, ultimately solving each polynomial division problem. The clear explanation and methodical approach make it an engaging and educational resource for understanding polynomial long division.

Takeaways
  • πŸ“š The video focuses on dividing polynomials using long division, starting with the example of dividing \(x^2 + 5x + 6\) by \(x + 2\).
  • πŸ“ The process begins by placing the divisor \(x + 2\) on the outside and the dividend \(x^2 + 5x + 6\) on the inside.
  • πŸ”’ The first step in long division is to divide the leading terms, \(x^2\) by \(x\), which equals \(x\).
  • βž— After dividing, the next step is to multiply the divisor \(x + 2\) by the result \(x\) and then subtract from the dividend.
  • βœ‚ The subtraction step eliminates the \(x^2\) term, leaving \(3x + 6\).
  • πŸ”„ The process repeats with dividing \(3x\) by \(x\), resulting in \(3\), and then multiplying and subtracting to simplify the expression further.
  • 🎯 The remainder after the final subtraction is zero, indicating that \(x + 3\) is the quotient for the division of \(x^2 + 5x + 6\) by \(x + 2\).
  • πŸ“ˆ The video continues with another example, dividing \(2x^3 + 8x^2 - 6x + 10\) by \(x - 2\), encouraging viewers to pause and try the problem themselves.
  • πŸ“‰ The method involves dividing each term by \(x\), multiplying the divisor by the result, and subtracting to simplify, repeating these steps until the remainder is found.
  • πŸ” When a remainder is present, it is included in the final answer, written as the remainder divided by the divisor.
  • πŸ“š The final example involves dividing \(6x^4 - 9x^2 + 18\) by \(x - 3\), with a reminder to be careful and to include all terms, including those with zero coefficients.
  • 🏁 The video concludes by summarizing the steps and providing the final answers for each polynomial division problem.
Q & A
  • What is the main topic of the video?

    -The main topic of the video is dividing polynomials using long division.

  • What is the first polynomial division example given in the video?

    -The first example is dividing \(x^2 + 5x + 6\) by \(x + 2\).

  • What is the result of the first polynomial division example?

    -The result of the first example is \(x + 3\).

  • What is the second polynomial division example in the video?

    -The second example is dividing \(2x^3 + 8x^2 - 6x + 10\) by \(x - 2\).

  • What is the quotient of the second polynomial division example?

    -The quotient of the second example is \(2x^2 + 12x + 18\).

  • What is the remainder of the second polynomial division example?

    -The remainder of the second example is \(46\).

  • What is the third polynomial division example discussed in the video?

    -The third example is dividing \(6x^4 - 9x^2 + 18\) by \(x - 3\).

  • What is the final answer for the third polynomial division example?

    -The final answer for the third example is \(6x^3 + 18x^2 + 45x + 145 + \frac{453}{x - 3}\).

  • What are the three main steps in polynomial long division?

    -The three main steps in polynomial long division are divide, multiply, and subtract.

  • What is the purpose of writing the remainder in the final answer of a polynomial division?

    -The purpose of writing the remainder is to show what is left over after the division process, which cannot be divided further by the divisor.

  • How does the video script guide the viewer to perform polynomial long division?

    -The video script guides the viewer through each step of the long division process with examples, explaining how to divide, multiply, and subtract terms at each stage.

Outlines
00:00
πŸ“š Dividing Polynomials Using Long Division

This paragraph introduces the concept of dividing polynomials using long division. The first example involves dividing \( x^2 + 5x + 6 \) by \( x + 2 \). The process begins by setting up the division with the divisor \( x + 2 \) on the outside and the dividend \( x^2 + 5x + 6 \) on the inside. The division starts by dividing the first term \( x^2 \) by \( x \), resulting in \( x \). This is followed by multiplying \( x \) by the divisor \( x + 2 \) and subtracting the result from the dividend. The process is repeated for the remaining terms, leading to a quotient of \( x + 3 \) and a remainder of zero. The method is then applied to a second example, dividing \( 2x^3 + 8x^2 - 6x + 10 \) by \( x - 2 \), where the viewer is encouraged to pause the video and attempt the division themselves.

05:02
πŸ” Continuing Polynomial Long Division with a Complex Example

The second paragraph continues the tutorial on polynomial long division with a more complex example. The task is to divide \( 2x^3 + 8x^2 - 6x + 10 \) by \( x - 2 \). The division starts by dividing \( 2x^3 \) by \( x \) to get \( 2x^2 \), and then multiplying \( 2x^2 \) by \( x - 2 \) and subtracting from the original polynomial. This process is repeated, with each term being divided by \( x \), multiplied by the divisor, and then subtracted from the current terms. The result is a quotient of \( 2x^2 + 12x + 18 \) and a remainder of 46, which is then expressed as \( 46 / (x - 2) \). The final answer is given as \( 2x^2 + 12x + 18 + 46 / (x - 2) \), which simplifies to \( 2x^3 + 8x^2 - 6x + 10 / (x - 2) \).

10:04
πŸ“˜ Advanced Polynomial Long Division with Remainders

The third paragraph presents an advanced example of polynomial long division with a remainder. The polynomial \( 6x^4 - 9x^2 + 18 \) is to be divided by \( x - 3 \). The division process involves setting up the division with the correct powers of \( x \), including zero powers where necessary. The division of \( 6x^4 \) by \( x \) yields \( 6x^3 \), and the subsequent multiplication and subtraction steps are carried out. The process is repeated for the \( x^3 \) term, resulting in \( 18x^3 \), and then for the \( x^2 \) term, leading to \( 45x^2 \). The remainder is calculated, and the final expression is simplified to \( 6x^3 + 18x^2 + 45x + 145 + 453 / (x - 3) \). The remainder \( 453 \) is included in the final answer, demonstrating how to handle polynomial division with non-zero remainders.

Mindmap
Keywords
πŸ’‘Polynomials
Polynomials are algebraic expressions consisting of variables and coefficients, involving only the operations of addition, subtraction, multiplication, and non-negative integer exponents of variables. In the video's context, polynomials are the main objects being divided using long division, with examples such as 'x squared plus 5x plus 6' and 'two x cubed plus eight x squared minus six x plus ten'.
πŸ’‘Long Division
Long division is a standard algorithm for dividing numbers, extended to polynomials in the context of this video. It involves breaking down the dividend (the polynomial to be divided) into multiples of the divisor (the polynomial by which it is being divided), and subtracting these multiples from the dividend to find the quotient and remainder. The video demonstrates this process step by step with several polynomial examples.
πŸ’‘Dividend
The dividend in the context of the video refers to the polynomial that is being divided. For instance, 'x squared plus 5x plus 6' is the dividend when it is divided by 'x plus 2'. The dividend is the starting point for the long division process, and it is broken down into parts that are multiples of the divisor.
πŸ’‘Divisor
The divisor is the polynomial by which the dividend is divided. In the script, 'x plus 2' serves as the divisor when dividing 'x squared plus 5x plus 6'. The divisor determines the pattern for subtracting multiples from the dividend to find the quotient.
πŸ’‘Quotient
The quotient is the result of the division process. In polynomial long division, it is the polynomial that represents how many times the divisor fits into the dividend without exceeding it. The video shows that the quotient for 'x squared plus 5x plus 6' divided by 'x plus 2' is 'x plus 3'.
πŸ’‘Remainder
A remainder is the part of the dividend that is left over after the division process when the divisor cannot fit into it any further. In the video, when dividing '2x cubed plus 8x squared minus 6x plus 10' by 'x minus 2', the remainder is '46', indicating that after subtracting multiples of the divisor, 46 is what remains.
πŸ’‘Exponents
Exponents indicate the number of times a base quantity is multiplied by itself. In the video, when dividing 'x squared' by 'x', the exponent 'two' is reduced by one to give 'x', illustrating the rule that any non-zero number raised to the power of zero is one.
πŸ’‘Distribute
Distribute refers to the process of multiplying each term inside a set of parentheses by an outside number and then adding the products. In the script, when multiplying 'x' by 'negative 2', the result is 'negative 2x', which is an example of distribution.
πŸ’‘Subtract
Subtraction is a fundamental arithmetic operation used in the long division of polynomials to eliminate terms. In the video, terms like 'x squared minus x squared' are subtracted to cancel each other out, simplifying the expression and moving towards the final quotient.
πŸ’‘Multiply
Multiplication is another basic arithmetic operation that is repeatedly used in the long division process. The video demonstrates multiplying terms like '2x squared times x' to get '2x cubed', which is a step in finding how many times the divisor fits into the dividend.
πŸ’‘Standard Order
Standard order refers to the arrangement of terms in a polynomial from the highest degree to the lowest. In the video, when dividing 'six x to the fourth' by 'x minus three', the polynomial is written in standard order, ensuring that each term is accounted for in the division process.
Highlights

Introduction to dividing polynomials using long division.

Dividing x squared plus 5x plus 6 by x plus 2 as the first example.

Placing the divisor (x plus 2) on the outside and the dividend (x squared plus 5x plus 6) on the inside.

Step-by-step guide starting with dividing x squared by x.

Subtracting exponents to simplify the division process.

Multiplying the result by the divisor and distributing the negative sign.

Subtracting terms to simplify and bring down the next term.

Continuing the process with dividing 3x by x and multiplying by the divisor.

Resulting in a remainder of zero and the quotient x plus 3.

Moving on to the second example: dividing two x cubed plus eight x squared minus six x plus ten by x minus two.

Dividing 2x cubed by x to get 2x squared and multiplying accordingly.

Subtracting terms to simplify and proceed to the next step.

Repeating the divide, multiply, and subtract steps for the polynomial.

Finalizing the division with a remainder of 46 and expressing the result.

Starting the third problem: dividing six x to the fourth minus nine x squared plus eighteen by x minus three.

Following the same steps for dividing higher degree polynomials.

Calculating the remainder and expressing the final answer.

Emphasizing the importance of careful calculation and checking with a calculator.

Conclusion on how to divide polynomials using long division.

Transcripts
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