MHF4U1 Unit 2 Lesson 6
Factoring
3.6
Learning
goal
• Know
the
remainder
theorem
• Know
the
factor
theorem.
Be
able
to
use
the
factor
theorem
to
factor
a
polyomial
of
degree
3
or
higher
Remainder
Theorem
When
a
polynomial
function
P(x)
is
divided
by
binomial
(x-‐‑a),
the
remainder
is
equal
to
f(a).
If
the
remainder
is
0,
then
x-‐‑a
is
a
factor
of
the
polynomial.
Factor
theorem
x-‐‑a
is
a
factor
of
f(x)
if
and
only
if
f(a)
=
0
Example
1
Determine
the
remainder
given
𝑓 (𝑥 ) = 2𝑥 ' − 4𝑥 * + 3𝑥 − 6
divided
by
(x+2)
Example
2
Confirm
that
(x+4)
is
a
factor
of
the
polynomial
function
𝑓 (𝑥 ) =
2𝑥 ' + 𝑥 * − 43𝑥 −
60.
Then
completely
factor
the
polynomial
and
sketch
the
function
1
MHF4U1 Unit 2 Lesson 6
Example
3–
Determine
a
factor
of
the
function
𝑓(𝑥 ) =
3𝑥 1 − 23𝑥 ' + 7𝑥 * + 155𝑥 + 50
.
Completely
factor
the
function,
and
sketch
the
function.
Example
4
–
The
function
𝑓(𝑥 ) =
3𝑥 ' + 𝑚𝑥 * − 41𝑥 + 𝑛
has
a
factor
of
(x-‐‑3).
When
it
is
divided
by
(x+2)
the
remainder
is
95.
Use
the
remainder
theorem
and
the
factor theorem to
determine the
values
of
m
and
n.