trig identities. what is an identity? identity: a statement of equality that is true as long as...
TRANSCRIPT
TRIG IDENTITIES
What is an identity?
Identity: a statement of equality that is TRUE as long as neither side is undefined.
Except when x = -1
Basic Identities
Why?
Other identities based on P.T. identity:
Cofunctions
A
B
Cofunction Identities
Sin(40) = Sin(-40)=
Cos(40)= Cos(-40)=
Even-Odd Identities
We will be doing 5 things with identities…
Evaluating – finding a value (numerical answer)
Simplifying – condensing (answer is usually a single trig function)
Factoring – un-doing the box/FOIL
Solving – getting “x” by itself (up to 4 possible solutions)
Verifying/Proving: showing that the left side and right side are equivalent.
Ex 1. Evaluate
Find the value of sine & cosine if
Ex 1. Find a trig function
Ex 2. Simplify
Ex 3. Factor
Ex.4 Solve
You Try
