Extra Help - Identities

As requested on the message board, here are solutions to 15.b and 15.c on p.155.

Identities are tricky, mainly because there isn't one certain strategy that will "always" work in order to find you the solution. You may find it helpful to adapt the following strategies as a plan to tackle identities. Ask yourself:

1. Are there any common factors?
2. Am I adding fractions? (find common denominator)
3. Are there any Pythagorean Identities that can be simplified?

If you try all of this and still don't have both sides equal to each other, then change everything in the problem into sines and cosines:

cscx = 1 / sinx

secx = 1 / cosx

tanx = sinx / cosx

cotx = cosx / sinx

After you have done that, if you have still not arrived at the solution, go through steps 1-3 one more time. Almost every question you will encounter in this course can be simplified using this strategy.

If you want some further practice beyond the identities on p.155, I suggest p.171 #14 a,c,e,f

The review questions assigned previously in class (a few posts down) are also good practice. The quiz is ONLY on chapters 4 and 6 - no sinusoidals this time.