Did this video help you?
Polynomial Division (Cambridge O Level Additional Maths)
Revision Note
Polynomial Division
What is polynomial division?
- Polynomial division is the process of dividing two polynomials
- This is usually only useful when the degree of the denominator is less than or equal to the degree of the numerator
- Polynomial division is a method for splitting polynomials into factor pairs
- (with or without a remainder term)
- The main uses of polynomial division are
- factorising polynomials
- simplifying 'top-heavy' algebraic fractions
How do I divide polynomials?
- The method used for polynomial division is just like the long division method for numbers
- sometimes called the 'bus stop method'
- The answer to a polynomial division question is built up term by term
- Start by dividing by the highest power term
- Write out this multiplied by the divisor and subtract
- Continue to divide by each reducing power term and subtracting your answer each time
- Continue until you are left with zero
- If the divisor is not a factor of the polynomial then there will be a remainder term left at the end of the division
Worked example
For the polynomial divide by and write the remainder.
Set up the polynomial division ('bus stop')
There is no term so write this as in the method.
There is no term so write this as in the method.
The first division step to consider is .
.Multiply by and subtract from .
Bring the down and divide by . Continue with each step until you are finished.
The remainder is 179.
Quadratic Divisor
What is meant by a quadratic divisor?
- Polynomial division usually involves dividing by a linear term
- a term of the form where is a constant and usually an integer
- It is possible to divide a polynomial by a quadratic term (and cubic, etc)
- this would be a term of the form where and are constants
- this is what is meant by a quadratic divisor
How do I divide by a quadratic divisor?
- The process is the same as for a linear divisor
- However, as will not divide into (in the polynomial division sense at least) the remainder, if there is one, could be of linear form, i.e. where and are constants
- It is possible that and so the remainder is still a constant
- However, as will not divide into (in the polynomial division sense at least) the remainder, if there is one, could be of linear form, i.e. where and are constants
Examiner Tip
- Give yourself plenty of room to do polynomial division
- Not only will this help avoid errors, it will make your working clear
- If you make a mistake and change something, fine, but if your method starts to get too messy it is best to restart
Worked example
Find the remainder when is divided by .
Set up the polynomial division ('bus stop') - there is no term so write this as in the method.
The first division step to consider is .
The remainder is .
You've read 0 of your 10 free revision notes
Unlock more, it's free!
Did this page help you?