pre-cal 20s december 10, 2008
DESCRIPTION
Factoring trinomials (a≠1), operations on rational expressions, non-permissible values.TRANSCRIPT
Reduced Speed Ahead by flickr user taberandrew
More about Rational Expressions
Operations on Rational Expressions
I Addition and Subtraction
• find a common denominator• add or subtract as required (watch your signs!)
... follow the same rules as operations on fractions (rational numbers)(although we don't
"really" subtract
anymore in high school)
SIGNS
Operations on Rational Expressions
II Mulitplication
• factor and reduce to simplest form• multiply numerators, then denominators
Remember! Any factor in
the numerator can reduce
with any factor in the
denominator
... follow the same rules as operations on fractions (rational numbers)
factor out a -1
Factor out -1
Operations on Rational Expressions
III Division• multiply the numerator by the reciprocal of the denominator (LOTS of
restrictions here!)
... follow the same rules as operations on fractions (rational numbers)
Reducing
RESTRICTIONS!
Don't upset the Math Ninja.
She's got a stick.
We "restrict" the variable (i.e. list the non-permissable values) to ensure there is no division by zero.
• restrict the denominatorsI Addition and Subtraction
RESTRICTIONS!
Don't upset the Math Ninja.
She's got a stick.
• restrict the denominatorsII Multiplication
We "restrict" the variable (i.e. list the non-permissable values) to ensure there is no division by zero.
RESTRICTIONS!
Don't upset the Math Ninja.
She's got a stick.
We "restrict" the variable (i.e. list the non-permissable values) to ensure there is no division by zero.
III Division• restrict everything except the numerator of the first fraction
Do you understand?Compare the graphs ...
Third: Reduce
Second: Restrictions?
First: Factor
First: Factor
Second: Restrictions?
Third: Reduce
Do you understand?Compare the graphs ...