# The Unit Circle

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question
On the unit circle, where 0
theta = (pi/2) and theta = (3pi/2)
question
Which of the following best explains why tangent of (5pi/6) DOES NOT equal tangent of (5pi/3)?
The angles do not have the same reference angle.
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Which of the following best explains why cosine of (2pi/3) DOES NOT equal cosine of (5pi/3)?
Cosine is negative in the second quadrant and positive in the fourth quadrant.
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What is the value of cosine of theta in the diagram below?
3/5
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What is the reference angle for a 240Â° angle?
60Â°
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Which of the following is true of the location of the terminal side of an angle, theta, whose sine value is 1/2?
theta has a reference angle of 30Â° and is in Quadrant I or II
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The terminal side of an angle measuring (pi/6) radians intersects the unit circle at what point?
(sqrt 3/2, 1/2)
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What is the value of sine theta in the diagram below?
24/25
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The radius of the circle below intersects the unit circle at (3/5, 4/5). What is the approximate value of theta?
53.1 degrees
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Which of the following is true of the values of x and y in the diagram below?
y/x = 1
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Which equation can be used to determine the reference angle, r, if theta=(7pi/12)?
r=pi-theta
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For which value of theta is sine of theta =-1?
3pi/2
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Which of the following explains why cosine of 60 = sine of 30 using the unit circle?
The side opposite a 30Â° angle is the same as the side adjacent to a 60Â° angle in a right triangle. On a unit circle, the y (sin) distance of a 30Â° angle is the same as the x (cos) distance of a 60Â° angle.
question
Which expression is equivalent to sine of 7pi/6)?