Pre-Calc 11: Rational Expressions - Chapter 6 This is a big topic that is really important for Pre-Calc 12. Take your time. Ask for help, please! A review … Rational expressions is just a fancy name for fractions. In grade 11, fractions take on a bit of a twist with adding variables in both the numerator and the denominator. It sounds harder than it is as grade 11 fractions almost always have some sort of cancelling out to happen to make the fraction simpler. For success in this chapter, it is important to review two things. Basic operations with fractions. If you feel like you need a quick review, please see this video. He does everything that you need for this course, including cross cancelling (which is a big deal this year and next) as well as not changing to mixed numbers (completely not useful in most math courses). Time for some practice: Please go here. You will need to check off the boxes for adding/subtracting and multiplying/dividing fractions before beginning. You may also wish to increase the time limit of 20 seconds. The other topic we have been reviewing the last two chapters – factoring. I haven’t added any other review here as you have done some over the last few weeks. If you feel like you could use some review, please refer back to the previous chapters. 6.1 Rational Expressions Rational expressions is just a fancy phrase for fractions. The twist in grade 11 is that the fractions will also now have variables in them. The other part to know is that when you see the word expression, it means to simplify. Non-permissible values. These refer to numbers that you are not allowed to have. When we are using fractions, it means that the denominator cannot equal zero because in our math system, we cannot divide by zero. Non-permissible values are only found in the denominator. The video for the most basic non-permissible values is here. Please also watch this video as it shows you the next level for non-permissible values. Simplifying rational expressions means to look for some possible canceling. Sometimes you will need to do some factoring first before any cancelling can occur. Remember that it has to look the exact same before it can be cancelled. As well, you will need to be able to state non- permissible values any time there is a variable in the denominator. Please view this video. The only part that he doesn’t do is to state the non-permissible values. EXTENSION Sometimes a rational expression will look very close but not identical in the numerator and denominator. You can try to use the additive inverse property to see if anything in the numerator and denominator can be cancelled. This video explains both the idea behind the additive inverse property and gives an example using a variable. If you just want to view the example using a variable, start the video at 1:18.
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Pre-Calc 11: Rational Expressions - Chapter 6
This is a big topic that is really important for Pre-Calc 12. Take your time. Ask for help, please!
A review …
Rational expressions is just a fancy name for fractions. In grade 11, fractions take on a bit of a
twist with adding variables in both the numerator and the denominator. It sounds harder than it
is as grade 11 fractions almost always have some sort of cancelling out to happen to make the
fraction simpler.
For success in this chapter, it is important to review two things.
Basic operations with fractions. If you feel like you need a quick review, please see this video.
He does everything that you need for this course, including cross cancelling (which is a big deal
this year and next) as well as not changing to mixed numbers (completely not useful in most
math courses).
Time for some practice: Please go here. You will need to check off the boxes for
adding/subtracting and multiplying/dividing fractions before beginning. You may also wish to
increase the time limit of 20 seconds.
The other topic we have been reviewing the last two chapters – factoring. I haven’t added any
other review here as you have done some over the last few weeks. If you feel like you could use
some review, please refer back to the previous chapters.
6.1 Rational Expressions
Rational expressions is just a fancy phrase for fractions. The twist in grade 11 is that the fractions
will also now have variables in them. The other part to know is that when you see the word
expression, it means to simplify.
Non-permissible values. These refer to numbers that you are not allowed to have. When we are
using fractions, it means that the denominator cannot equal zero because in our math system, we
cannot divide by zero. Non-permissible values are only found in the denominator. The video
for the most basic non-permissible values is here. Please also watch this video as it shows you the
next level for non-permissible values.
Simplifying rational expressions means to look for some possible canceling. Sometimes you will
need to do some factoring first before any cancelling can occur. Remember that it has to look
the exact same before it can be cancelled. As well, you will need to be able to state non-
permissible values any time there is a variable in the denominator. Please view this video. The
only part that he doesn’t do is to state the non-permissible values.
EXTENSION
Sometimes a rational expression will look very close but not identical in the numerator and
denominator. You can try to use the additive inverse property to see if anything in the
numerator and denominator can be cancelled. This video explains both the idea behind the
additive inverse property and gives an example using a variable. If you just want to view the
example using a variable, start the video at 1:18.