Which equation can be used to determine the reference angle, r , if theta is equal to 7 pi over 12 ?
Answer
A
r is equal to theta minus pi
B
r is equal to 2 pi minus theta
C
r is equal to theta
D
r is equal to pi minus theta
Explanation
Since 7π/12 is between π/2 and π, θ lies in Quadrant II. The reference angle in Quadrant II is the difference between π and θ, so use r = π − θ; this is choice D.
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