2. When dividing two polynomials, we get
a quotient polynomial and a remainder
polynomial.
Written: Remainder
Divisor
Quotient
The degree of the remainder must be
less than the degree of the divisor.
3. Write in the same format as dividing
numbers.
Remember:
4. Use a 0 coefficient for missing terms.
Divide the 1st term of the dividend by the
1st term of the divisor.
Example: Divide by
9. Use synthetic substitution to evaluate
Now use long division to divide
10. If a polynomial f(x) is divided by x – k,
then the remainder is r = f(k).
We just noticed the remainder when f(x)
was divided by x – 2 was 15 and also
f(2) = 15, so r =f(k).
We also noticed the other numbers
resulting from synthetic substitution
were the coefficients of the quotient.
We can use this to divide polynomials!
11. Can be used to divide a polynomial by
an expression of the form x – k.
Example:
12. Use synthetic division to divide
by x – 1
by x + 2
14. A polynomial f(x) has a factor x – k if
and only if f(k) = 0.
(when r = 0 for f(x) divided by x – k)
For example: Dividing
gives a quotient of with no
remainder.
Therefore:
15. Factor
Since f(-3) = 0, we know x – (-3) or
x+3 is a factor of f(x).
Use synthetic division to find other
factors.
18. Remember: a zero is an x value for
which f(x) = 0
To find zeros, factor completely, then
set each factor equal to zero and solve.
Example: One zero of
is x = 2. Find the other zeros.