Identities!

Last week we learned mainly about Identities.

The most important of identities used are the reciprocal relationships, Pythagorean relationships, and the co-function relationships.

In order to remember these, you should either memorize them or write them on flashcards.

The Reciprocal Relationships-

scs x=1/sin x

sec x=1/cox x

cot x=1/tan x

The Pythagorean Relationships-

sin^2+cos^2 x=1

1+tan^2 x=sec^2 x
1+cot^2 x=csc^2 x

The Co-Function Relationships-

sin x=cos (90-0) and cos x=sin (90-0)

tan x=cot (90-0) and cot x=tan (90-0)

sec x= csc (90-0) and csc x=sec (90-0)

Steps to Solve-

1. Look for any algebra to solve.

2. Look for any identities. (First try Pythagorean, if that does not work try to change everything to sin and cos.)

3. Look for any algebra to solve.

4. Look for any identites.

5. Repeat this until simplified all the way.

You amy not use all of these steps every single time.