Chapter 4 Section 3

Chapter 4 Section 3 is essentially about taking two things and proving that they are the same thing...

Notes from class as well as example problems are available here:
http://www.nickloui.com/precalc/4.3.htm

Examples #1 and #2 are an example of "Transforming one expression to another"
Example #3 is an "Identity" problem. The difference between this type of problem is that you can work with either side of the equation to work on.

Most of this section is simply built from the trignometric relations that we learned in Section 2.

An Example?

Show the steps necesary to transform the expression on the left into the one on the right.

sin(x)cot(x) to cos(x)

1) sin(x) * cos(x)/sin(x)
2) the sin(x) crosses out leaving just cos(x)

More...
http://www.intmath.com/Add_Trig/1_TrId.php provides another explanation to Trigonometric Identities as well as information on proving them. (and the pictures are really big... yay)

Navjit-- you're up next!

Here's a YouTube video that is absolutely hilarious-- for when feel like taking a break from studying for Precalc :) .