Section 5.4--Factoring Quadratic Expressions
Factoring
Factoring-rewriting an expression as the product of its factors
GCF-common factor of the terms of the expression (greatest coefficient and
greatest exponent)
Example 1
Factor:
Quick Check 1
Quadratic Trinomials
Can often factor into two binomial factors
•find two factors with product ac and sum b
•If ac and b are both POSITIVE, then both factors are positive
Quick Check 2
•If ac is POSITIVE and b is NEGATIVE, then the factors of ac are both negative
Quick Check 2
•If ac is NEGATIVE, then the factors have different signs (one positive, one
negative)
Quick Check 3
•If ac is POSITIVE, factors have same sign even of a=1
Quick Check 4
•If ac is NEGATIVE, factors have different signs
Factoring Special Expressions
•perfect square Trinomials--product you obtain when you square a trinomial
•middle term is twice the product of the terms of the binomial
Example 5
Difference of Two Squares
•an expression on the form
Example 6
Assignment: #1-75 odd; pg 268 #48, 66, 71