Review of chapter 8-4

Chapter 8-4 was the hardest section for me so i decided to review it.

Relationships among functions.
To find relationships among functions you use identities. Identities is another word for a bunch of formulas that show how trig functions and can be used with other trig functions and how they relate. Usisng these formulas you follow the steps and do some algebra to come up with a more simplified version of the problem. You will sometimes be asked to simplify wear you just simplify the equation down to the smalles you can get it or will be asked to prove which means you only have to show the steps of how to get the answer they've already given you. These are the steps that you should follow.
1.Algebra
2.Identities-try pythagorean first. If it doesnt work try to change all to sin and cos
3.Algebra
4.Identities and so on repeat until all the way simplified

Identities:
Pythagorean
sin^2@+cos^22=1 1+tan^2@=sec^2@

1+cot^2@=csc^2@

Reciprical
csc@=1/sin@ secf=1/cos@

cot@=1/tan@

Cofunction
sin@=cos(90-@) cos@sin(90-@)
tan@=cot(90-@) cot@=tan(90-@)
sec@=csc(90-@) csc@=sec(90-@)

Ex1
sec^2@-1
This goes with pythagorean formula. If rearraged formulas states that 1+tan^2@=sec^2@
There fore this equation is simplified to tan^2@