Understanding Reference Angles and Trigonometric Signs

In which quadrant are both the cosine and sine values positive?

• Quadrant II

• Quadrant I

• Quadrant III

• Quadrant IV

What is a reference angle?

• An angle that is always 180°

• A positive acute angle associated with a non-quadrantal angle

• An angle greater than 90°

• An angle that is always negative

How do you find the reference angle for an angle in Quadrant III?

• Subtract the angle from 360°

• Subtract the angle from 180°

• Subtract the angle from 90°

• Subtract 180° from the angle

If an angle is 150°, what is its reference angle?

• 30°

• 60°

• 90°

• 120°

What is the reference angle for 2π/3 radians?

• π/4

• π/2

• π/3

• π/6

In which quadrant is the sine value negative and the cosine value positive?

• Quadrant IV

• Quadrant I

• Quadrant II

• Quadrant III

How can reference angles help in finding the sine and cosine of angles larger than 90°?

• By converting them to degrees

• By using the reference angle and knowing the quadrant

• By adding 90° to the reference angle

• By subtracting the reference angle from 360°

What is the sine of 150° if the sine of its reference angle is 1/2?

• -1/2

• 1/2

• -1

• 0

If the cosine of π/3 is 1/2, what is the cosine of 5π/3?

• 0

• 1/2

• -1/2

• -1

Why is it important to know the quadrant when using reference angles?

• To know the sign of sine and cosine values

• To find the angle's reference angle

• To convert the angle to radians

• To determine the angle's size