Question 1

Which of the following is the reference angle for $$-130^	ext{o}$$?

Accepted Answer

$$50^	ext{o}$$

Question 2

What is the reference angle for $$13\pi/18$$ radians?

Accepted Answer

$$5\pi/18$$

Question 3

Express $$\sin 210^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$-\sin 30^	ext{o}$$

Question 4

Express $$\sec 150^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$-\sec 30^	ext{o}$$

Question 5

Which of the following is the reference angle for $$-140^	ext{o}$$?

Accepted Answer

$$40^	ext{o}$$

Question 6

Express $$\cos 240^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$-\cos 60^	ext{o}$$

Question 7

A surveyor measures an angle of $$150^	ext{o}$$ from the positive x-axis. What is the reference angle, and in which quadrant does the terminal side lie?

Accepted Answer

Reference angle: $$30^	ext{o}$$, Quadrant II

Question 8

Express $$	an \frac{5\pi}{4} in $$terms of its reference angle.

Accepted Answer

$$-	an \frac{\pi}{4}$$

Question 9

Express $$\sin -\frac{5\pi}{4} in $$terms of its reference angle.

Accepted Answer

$$-\sin \frac{\pi}{4}$$

Question 10

Express $$\cos -\frac{\pi}{4} in $$terms of its reference angle.

Accepted Answer

$$\cos \frac{\pi}{4}$$

Question 11

A pilot turns the plane to a heading of $$135^	ext{o}. $$What is the reference angle, and what is the sign of $$\sin 135^	ext{o}$$?

Accepted Answer

Reference angle: $$45^	ext{o}$$, $$\sin 135^	ext{o} is $$positive

Question 12

Express $$\csc 135^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$\csc 45^	ext{o}$$

Question 13

Which of the following is the reference angle for $$11\pi/12$$ radians?

Accepted Answer

$$\pi/12$$

Question 14

Express $$\cos \frac{-\pi}{4} in $$terms of its reference angle.

Accepted Answer

$$\cos \frac{\pi}{4}$$

Question 15

A construction worker rotates a beam $$7\pi/12$$ radians from the positive x-axis. What is the reference angle?

Accepted Answer

$$5\pi/12$$

Question 16

Express $$\sin 150^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$\sin 30^	ext{o}$$

Question 17

Express $$	an 5\pi/4 in $$terms of its reference angle.

Accepted Answer

$$-	an \pi/4$$

Question 18

A clock's minute hand points at $$-5\pi/3$$ radians. What is the reference angle?

Accepted Answer

$$\pi/3$$

Question 19

Express $$\sin 135^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$\sin 45^	ext{o}$$

Question 20

Express $$\sec 150^	ext{o} in $$terms of its reference angle.

Accepted Answer

$$-\sec 30^	ext{o}$$

Reference Angles and Trigonometric Functions: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards