MTH 095 - May 5, 2009
1.
Today we will . . .
- go over HW questions 5.6 (second assignment)
- talk about some special cases of factoring (5.7)
2.
Next HW Quiz is tomorrow
Will cover Sections 7.2, 7.3, 5.4 - 5.6 (both assignments)
Jan 4­5:52 PM
May 5­10:05 AM
1
May 5­10:10 AM
Sec 5.7: Factoring by Special Products
We have seen how to factor trinomial and how to factor out a GCF.
There are a couple of special cases that are quick to factor if you
recognize them:
(1)
(2)
Perfect square trinomials
Difference of two squares
NOTE: We will NOT factor the sum or difference of two cubes.
You can skip that type when reading Sec 5.7.
May 1­9:48 AM
2
First we look at perfect square trinomials.
EXAMPLE: Multiply the following and look for a pattern:
(a)
(x + 1)2
(b)
(4y - 3)2
(c)
(2a + 5b)2
May 1­9:50 AM
EXAMPLE: Factor these trinomials.
(a)
x2 - 14x + 49
(b)
9w2 + 24w + 16
(c)
x2 - 4xy + 4y2
May 4­9:06 AM
3
Now you try one!
Factor
4x2 + 20x + 25
May 5­9:18 AM
Now let's consider the second special case. First we'll multiply.
EXAMPLE: Multiply and look for a pattern.
(a)
(x + 3)(x - 3)
(b)
(5a - 2b)(5a + 2b)
May 4­9:10 AM
4
EXAMPLE: Factor.
(a)
t2 - 100
(b)
9x2 - 16
(c)
25n2 - 36p2
May 5­9:17 AM
Now you try one!
Factor
81a2 - 25b2
May 5­9:20 AM
5
Attachments
Student Guide to Online Math Help Spring 2009.pdf