The Unit Circle

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.

What is the value of tangent of theta in the unit circle below?

sqrt of 3/3

The terminal side of an angle measuring (pi/6) radians intersects the unit circle at what point?

(sqrt 3/2, 1/2)

What is the value of sine theta in the diagram below?

24/25

What is the value of cosine of theta in the diagram below?

3/5

For which value of theta is sine of theta =-1?

3pi/2

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

What is the reference angle for a 240° angle?

60°

Which of the following best explains why cosine of 2pi/3 DOES NOT EQUAL cosine of 5pi/3?

IT IS NOT The angles do not have the same reference angle.

On the unit circle, where 0<theta< or = 2pi, when is mc007-2.jpg undefined?

theta = (pi/2) and theta = (3pi/2)

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 30° and is in Quadrant I or II

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.

Which expression is equivalent to sine of 7pi/6)?

IT IS NOT sine of (5pi/3)

Which equation can be used to determine the reference angle, r, if theta=(7pi/12)?

r=pi-theta

Which expression can be used to determine the reference angle for an angle, x, measuring 150°?

180 degrees - x

Which of the following explains why cosine of 60 = sine of 30 using the unit circle?

The side opposite a 30° angle is the same as the side adjacent to a 60° angle in a right triangle. On a unit circle, the y (sin) distance of a 30° angle is the same as the x (cos) distance of a 60° angle.

Which of the following is true of the values of x and y in the diagram below?

y/x = 1