1 Undefined Fractions.notebook
February 06, 2013
Do Now:
8 =
4
0 =
4
0 =
4 =
8 8
4
4 =
=
4 0
8 =
8
8 =
0
Jan 12­2:04 PM
Date:
Algebraic Fractions:
Undefined
A fraction that has no meaning
Objective: Find values of variables for which an algebraic fraction is undefined. (AA15)
Sep 29­7:38 AM
1
1 Undefined Fractions.notebook
February 06, 2013
Algebraic fraction - quotient of two
algebraic expressions
A fraction is undefined when the
denominator is equal to zero.
1. Ignore numerator;Set denominator = 0
(undefined: set underneath = 0)
2. Solve
3. Check
Aug 23­9:02 PM
1)
Find a value for x that makes
6 undefined
7-x
Ignore numerator (top)
7 - x = 0
Set Denominator = 0
(Undefined: Underneath = 0)
7 - x = 0
Solve for x
+ x +x
7 = x
x = 7
Check answer
Aug 23­9:02 PM
2
1 Undefined Fractions.notebook
February 06, 2013
2) Find the value of x that makes the fraction
12x
undefined:
5+x
Set denominator = 0
Solve
5+x=0
-5
-5
x = -5
Check answer
Aug 23­9:02 PM
Find the value of x that makes these
fractions undefined:
3)
3xy
2x - 4
4)
3x + 7
10 - 2x
Aug 23­9:02 PM
3
1 Undefined Fractions.notebook
February 06, 2013
Find the value of x that makes these
fractions undefined:
5)
2x - 15
6x
6)
5x + 1
3x - 1
Aug 23­9:02 PM
Find the value of x that makes these
fractions undefined:
7)
8
x
8)
-8
9x
Aug 23­9:02 PM
4
1 Undefined Fractions.notebook
February 06, 2013
9) Which expression is undefined when x = 2?
A) 1
x-2
C) x
2
B) x - 2
D) x0
10) Which expression is undefined when x = 6?
A) 1
x-6
B) x0
C) x - 6
D) 1
x+6
Aug 23­9:02 PM
Find the value of x that makes these
fractions undefined:
11)
15
x2
12)
1
x-6
Aug 23­9:02 PM
5