Pre-Calculus 3.17.10

Using Trig Identities, Day 2

Okay, friends, today's lesson was a continuation of yesterday's introduction to Trig Identities. I'm going to go step-by-step through a couple of examples from today's class, in order for you to best understand:

EXAMPLE #1:




1.) First, decide which side of the equation is more complicated--in this case, the RIGHT side.

2.) Next, find the trig identity for the numerator of the fraction on the right.




In this case, using the trig identity list, you will find that is , and the denominator remains .

3.) In order to continue, split up the numerator. splits into the following, so if the numerators of the following fractions are multiplied, they would be squared.



4.) Now, when you refer back to the trig identities list, you will find that is

5.) Finally, you are left with .

EXAMPLE #2:



1.) Decide which side of the equation is most complicated--in this case, the LEFT side.

2.) Next, by referring to the trig identity sheet, you will find that the numerator of the fraction can be changed from to .

Now, it is going to look like this:

(Don't you dare even consider cancelling, here.)


3.) Next, factor the top, so it will now look like this...

4.) Now you may continue by cancelling, so you are left with...

5.) Finish up by distributing the negative sign (right outside of the parenthesis) to the items inside the parenthesis.

You should end up with the following:

To see the notes from today's class, click HERE to go to Mr. Corn's web page