Factoring - Perfect Square Trinomial
• A Perfect Square Trinomial is any trinomial that is the
result of squaring a binomial.
 
2
3
x 
Binomial
Squared
2
6 9
x x
  
Perfect Square
Trinomial
2 2
2
a ab b
 
• Our goal now is to start with a perfect square trinomial
and factor it into a binomial squared. Here are the
patterns.
Perfect Square
Trinomial
Factored
 
2
a b
 
2 2
2
a ab b
   
2
a b
 
Note the pattern for the signs:
• Here is how to identify a perfect square trinomial:
1. Both first and last terms are perfect squares
2 2
2
a ab b
  2 2
2
a ab b
 
2. The middle term is given by 2ab
If these two conditions are met, then the
expression is a perfect square trinomial.
Note that there is always a positive sign on
both of these terms.
• Example 1
2
8 16
x x
 
Factor:
Determine if the trinomial is a perfect square
trinomial.
1. Are both first and last terms perfect squares?
2. Is the middle term 2 ?
ab
2
8 16
x x
     
2 2
8 4
x x
  
2ab 2( )(4)
x
 8x

• Since the trinomial is a perfect square, factor it using
the pattern:
1. First term a:
2. Last term b:
(x
( 4)
x
3. Sign same as
the middle term
( 4)
x 
4. Squared
2
( 4)
x 
 
2
2 2
2
a ab b a b
   
   
2 2
8 4
x x
 
• Example 2
2
10 25
x x
 
Factor:
Determine if the trinomial is a perfect square
trinomial.
1. Are both first and last terms perfect squares?
2. Is the middle term 2 ?
ab
2
10 25
x x
     
2 2
10 5
x x
  
2ab   
2 5
x
 10x

• Since the trinomial is a perfect square, factor it using
the pattern:
1. First term:
2. Last term
(x
( 5)
x
3. Sign same as
the middle term
( 5)
x 
4. Squared
2
( 5)
x 
 
2
2 2
2
a ab b a b
   
   
2 2
10 5
x x
 
• Example 3
Factor:
Determine if the trinomial is a perfect square
trinomial.
1. Are both first and last terms perfect squares?
2. Check the middle term:
2 2x
 3

2
4 12 9
x x
 
12x

2ab 
• Since the trinomial is a perfect square, factor it using
the pattern:
1. First term:
2. Last term
(2x
(2 3)
x
3. Sign same as
the middle term
(2 3)
x 
4. Squared
2
(2 3)
x 
 
2
2 2
2
a ab b a b
   
2
4 12 9
x x
 
• Example 4
Factor:
Determine if the trinomial is a perfect square
trinomial.
1. Are both first and last terms perfect squares?
2. Check the middle term: 2 2x
 3

2
4 7 9
x x
 
12x
 No
This is not a perfect square trinomial. If it can be
factored, another method will have to be used.
• Example 5
Factor:
Determine if the trinomial is a perfect square
trinomial.
1. Are both first and last terms perfect squares?
2
9 20 12
x x
 
This is not a perfect square trinomial. If it can be
factored, another method will have to be used.
No
• Example 6
Factor:
Determine if the trinomial is a perfect square
trinomial.
2
10 25
x x
 
This is not a perfect square trinomial since the last
term has a negative sign.
Perfect square trinomials always have a positive
sign for the last term.
• Example 7
Factor:
Determine if the trinomial is a perfect square
trinomial.
1. Are both first and last terms perfect squares?
2. Check the middle term:
2 5x
 6y

2 2
25 60 36
x xy y
 
60xy

• Since the trinomial is a perfect square, factor it using
the pattern:
1. First term:
2. Last term
(5x
(5 6 )
x y
3. Sign same as
the middle term
(5 6 )
x y

4. Squared
2
(5 6 )
x y

 
2
2 2
2
a ab b a b
   
2 2
25 60 36
x xy y
 
1PerfSqTri.ppsx

1PerfSqTri.ppsx

  • 1.
    Factoring - PerfectSquare Trinomial • A Perfect Square Trinomial is any trinomial that is the result of squaring a binomial.   2 3 x  Binomial Squared 2 6 9 x x    Perfect Square Trinomial
  • 2.
    2 2 2 a abb   • Our goal now is to start with a perfect square trinomial and factor it into a binomial squared. Here are the patterns. Perfect Square Trinomial Factored   2 a b   2 2 2 a ab b     2 a b   Note the pattern for the signs:
  • 3.
    • Here ishow to identify a perfect square trinomial: 1. Both first and last terms are perfect squares 2 2 2 a ab b   2 2 2 a ab b   2. The middle term is given by 2ab If these two conditions are met, then the expression is a perfect square trinomial. Note that there is always a positive sign on both of these terms.
  • 4.
    • Example 1 2 816 x x   Factor: Determine if the trinomial is a perfect square trinomial. 1. Are both first and last terms perfect squares? 2. Is the middle term 2 ? ab 2 8 16 x x       2 2 8 4 x x    2ab 2( )(4) x  8x 
  • 5.
    • Since thetrinomial is a perfect square, factor it using the pattern: 1. First term a: 2. Last term b: (x ( 4) x 3. Sign same as the middle term ( 4) x  4. Squared 2 ( 4) x    2 2 2 2 a ab b a b         2 2 8 4 x x  
  • 6.
    • Example 2 2 1025 x x   Factor: Determine if the trinomial is a perfect square trinomial. 1. Are both first and last terms perfect squares? 2. Is the middle term 2 ? ab 2 10 25 x x       2 2 10 5 x x    2ab    2 5 x  10x 
  • 7.
    • Since thetrinomial is a perfect square, factor it using the pattern: 1. First term: 2. Last term (x ( 5) x 3. Sign same as the middle term ( 5) x  4. Squared 2 ( 5) x    2 2 2 2 a ab b a b         2 2 10 5 x x  
  • 8.
    • Example 3 Factor: Determineif the trinomial is a perfect square trinomial. 1. Are both first and last terms perfect squares? 2. Check the middle term: 2 2x  3  2 4 12 9 x x   12x  2ab 
  • 9.
    • Since thetrinomial is a perfect square, factor it using the pattern: 1. First term: 2. Last term (2x (2 3) x 3. Sign same as the middle term (2 3) x  4. Squared 2 (2 3) x    2 2 2 2 a ab b a b     2 4 12 9 x x  
  • 10.
    • Example 4 Factor: Determineif the trinomial is a perfect square trinomial. 1. Are both first and last terms perfect squares? 2. Check the middle term: 2 2x  3  2 4 7 9 x x   12x  No This is not a perfect square trinomial. If it can be factored, another method will have to be used.
  • 11.
    • Example 5 Factor: Determineif the trinomial is a perfect square trinomial. 1. Are both first and last terms perfect squares? 2 9 20 12 x x   This is not a perfect square trinomial. If it can be factored, another method will have to be used. No
  • 12.
    • Example 6 Factor: Determineif the trinomial is a perfect square trinomial. 2 10 25 x x   This is not a perfect square trinomial since the last term has a negative sign. Perfect square trinomials always have a positive sign for the last term.
  • 13.
    • Example 7 Factor: Determineif the trinomial is a perfect square trinomial. 1. Are both first and last terms perfect squares? 2. Check the middle term: 2 5x  6y  2 2 25 60 36 x xy y   60xy 
  • 14.
    • Since thetrinomial is a perfect square, factor it using the pattern: 1. First term: 2. Last term (5x (5 6 ) x y 3. Sign same as the middle term (5 6 ) x y  4. Squared 2 (5 6 ) x y    2 2 2 2 a ab b a b     2 2 25 60 36 x xy y  