Scribe Post 3/24

Hello Everybody,

Today we went over more problems from 3.2, namely verifying and identifying rational identities.

Rational Identity: Trigonometric expressions that are equal fractions set on either side of an equal sign.

here's an example from page 177 in your trig book

cos(a)/(1-sin(a)) = (1+sin(a))/ cos (a) where (a) equals alpha

(cos(a)/1-sin(a)) x (1+ sin (a)/ (1+ sin(a)) = (1+sin(a))/ cos (a) x (1+sin(a))/ (1+sin(a))

Multiply both sides with either the numerator or denominator of the opposite side (in this case numerator of left side) to get like terms

cos (a) (1+sin (a)/ cos^2(a)= (1+sin(a))/ cos (a) Here you use your knowledge of the Fundamental Pythagorean Identity {sin^2(a) + cos^2 (a)=1 } to solve (all trig identities are in the very last page of our textbook)

(1+sin(a))/cos(a) = (1+sin(a))/ cos(a) YAY IT WORKED!

We also did example 5 on page 177 in your textbook. The main difference with that problem is that you have to know to split up the fraction identity:

(csc(x)-sin(x))/ sin (x) becomes csc(x)/sin(x) - sin(x)/sin(x)

Here's a youtube video of a guy doing various different types of identity problems(specifically identity problems with fractions like above).

http://www.youtube.com/watch?v=OJz-fOzFbEc&feature=PlayList&p=2AFAB7497192607A&index=19&playnext=2&playnext_from=PL

JoJo would like to remind everyone that he is in his room Wednesday and Thursday at lunch and break to help anyone who needs it. Remember to get your Flickr, and Pbworks stuff in as that's being checked as we speak. Get help now, we have a TEST next Friday.

Next scribe is Emma