3.8 Fundamental Identities. –A trig identitiy is a trig equation that is always true –We can prove an identity using the definitions of trig functions (they use x, y, and r). Ex 1) Use definitions to prove:. We also have the Pythagorean Identities. “I tan in a second”.
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–We can prove an identity using the definitions of trig functions
(they use x, y, and r)
Ex 1) Use definitions to prove:
“I tan in a second”
(get by ÷ by cos2θ)
“I cotan in a cosecond”
(get by ÷ by sin2θ)
We can prove identities (using θ, ϕ, β, etc) or verify the identity using specific values.
Ex 2) Use exact values to verify the identity for the given θ
(try ratio & reciprocal)
Pythag (1 + tan2θ = sec2θ)
#308 Pg 169 #1–45 odd
Hints for HW Make sure calculator is in correct MODE
Draw those reference triangle pictures!