Chapter 3
Section 1--Reference Angle
The reference angle (aka the related angle) for any angle θ in standard position
is the acute angle between the terminal side of θ and the x-axis.
The book uses θ; we use θr .
Example 1 -- Name the reference angle
a) 300
b) 1350
c)2400
Example 2 -- Find the exact value of sin 2400
Example 3 -- Find the exact value of tan 3150
Example 4 -- Find the exact value of csc 3000
Example 5 -- Find the exact value of cos 4950
d) 3300
e) -2100
f) -1400
Example 6 -- Use a calculator to find (to the nearest ten-thousandth)
a) sin 2500
b) cos -1600
c) csc 2500
Example 7 -- Find θ if sin θ= -.5592 and θ ∈ QIII (to the nearest degree)
Example 8 -- Find θ if tan θ= -.8541 and θ ∈ QIV
Example 9 -- Find θ if sec θ= 3.8637 and θ ∈ QIV
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