Review Lessons
1. Trigonometric Functions and Identities
Watch Video Lesson
2. Unit Circle and Trig Values
Watch Video Lesson
Practice Problems
Problem 3Basic
Find the value of the following trig functions:
(a) \( \cot 0 \) (b) \( \sec \frac{\pi}{4} \) (c) \( \csc \frac{\pi}{6} \) (d) \( \sec \frac{\pi}{3} - \cot \frac{\pi}{4} \) (e) \( \cos \frac{7\pi}{6}-\frac{1}{2}\cot \frac{5\pi}{6} \)
Watch Solution
(a) \( \cot 0 \) (b) \( \sec \frac{\pi}{4} \) (c) \( \csc \frac{\pi}{6} \) (d) \( \sec \frac{\pi}{3} - \cot \frac{\pi}{4} \) (e) \( \cos \frac{7\pi}{6}-\frac{1}{2}\cot \frac{5\pi}{6} \)
Problem 4Basic
Find the exact value of each of the following trig functions:
(a) \( \tan \frac{9\pi}{4} \) (b) \( \cos \frac{19\pi}{6} \) (c) \( \sin \frac{11\pi}{4} \) (d) \( \sec \frac{10\pi}{3} \) (e) \( \csc \frac{17\pi}{3} \)
Watch Solution
(a) \( \tan \frac{9\pi}{4} \) (b) \( \cos \frac{19\pi}{6} \) (c) \( \sin \frac{11\pi}{4} \) (d) \( \sec \frac{10\pi}{3} \) (e) \( \csc \frac{17\pi}{3} \)
Problem 5Intermediate
Find the exact value of each of the following expressions:
(a) \(\tan 40^{\circ} \cdot \dfrac{\csc 40^{\circ}}{\cos 40^{\circ}} \cdot \dfrac{1}{\sec^2{40}}\)
(b) \({\sin \dfrac{\pi}{5} + \cos \dfrac{\pi}{5}}\: \tan \left(-\dfrac{\pi}{5}\right)\)
Watch Solution
(a) \(\tan 40^{\circ} \cdot \dfrac{\csc 40^{\circ}}{\cos 40^{\circ}} \cdot \dfrac{1}{\sec^2{40}}\)
(b) \({\sin \dfrac{\pi}{5} + \cos \dfrac{\pi}{5}}\: \tan \left(-\dfrac{\pi}{5}\right)\)
Problem 6Intermediate
Find the exact value of each of the following expressions:
(a) \(\tan 10^\circ -\dfrac{\sin 10^\circ}{\cos 10^\circ}\) (b) \(\cos^2 \frac{\pi}{5} +\dfrac{1}{\csc^2 \frac{\pi}{5}}\)
(c) \(\sec^2 40^\circ - \tan^2 40^\circ\) (d) \(\tan 10^\circ \cos 10^\circ \csc 10^\circ \)
Watch Solution
(a) \(\tan 10^\circ -\dfrac{\sin 10^\circ}{\cos 10^\circ}\) (b) \(\cos^2 \frac{\pi}{5} +\dfrac{1}{\csc^2 \frac{\pi}{5}}\)
(c) \(\sec^2 40^\circ - \tan^2 40^\circ\) (d) \(\tan 10^\circ \cos 10^\circ \csc 10^\circ \)
Problem 7Intermediate
Evaluate each expression without using a calculator:
(a) \(2\sec (\pi/3)-\tan (3\pi/4) \)
(b) \(2\tan (\pi/4) - \dfrac{1}{2\tan(-5\pi/4)} +\sin (5\pi/6) \)
Watch Solution
(a) \(2\sec (\pi/3)-\tan (3\pi/4) \)
(b) \(2\tan (\pi/4) - \dfrac{1}{2\tan(-5\pi/4)} +\sin (5\pi/6) \)
Problem 8Intermediate
Evaluate each expression without using a calculator:
(a) \(\tan ( -7\pi/4) \cdot \cos (4\pi/3) - \sin (5\pi/6)\cdot \sin (3\pi/2) \)
(b) \( \sin (7\pi/6) + \cos (-\pi/3)-\csc^2(\pi/2) \)
Watch Solution
(a) \(\tan ( -7\pi/4) \cdot \cos (4\pi/3) - \sin (5\pi/6)\cdot \sin (3\pi/2) \)
(b) \( \sin (7\pi/6) + \cos (-\pi/3)-\csc^2(\pi/2) \)
Problem 9Identities
Simplify the trigonometric expressions:
(a) \(\cos \theta \cdot \csc \theta \cdot \tan \theta \)
(b) \(\sec\theta - \sec\theta \sin^2\theta \)
(c) \( (\sin \theta + \cos \theta)^2 + (\sin \theta - \cos \theta)^2\)
Watch Solution
(a) \(\cos \theta \cdot \csc \theta \cdot \tan \theta \)
(b) \(\sec\theta - \sec\theta \sin^2\theta \)
(c) \( (\sin \theta + \cos \theta)^2 + (\sin \theta - \cos \theta)^2\)
Problem 10Identities
Simplify the trigonometric expressions:
(a) \(\dfrac{\sin \theta-\sin^3 \theta}{\cos^2 \theta}\) (b) \( 1 -\dfrac{\sin^2\theta}{1+\cos\theta} \)
Watch Solution
(a) \(\dfrac{\sin \theta-\sin^3 \theta}{\cos^2 \theta}\) (b) \( 1 -\dfrac{\sin^2\theta}{1+\cos\theta} \)
Problem 11Identities
Simplify the trigonometric expressions:
(a) \(\tan\theta + \dfrac{\cos\theta}{1+\sin\theta}\) (b) \(\dfrac{1-\cos\theta}{\sin\theta}+\dfrac{\sin\theta}{1-\cos\theta}\)
Watch Solution
(a) \(\tan\theta + \dfrac{\cos\theta}{1+\sin\theta}\) (b) \(\dfrac{1-\cos\theta}{\sin\theta}+\dfrac{\sin\theta}{1-\cos\theta}\)
Problem 12Inverse Trig
Find the exact value of each expression in radians:
(a) \( \sin^{-1} (1)\) (b) \(\sin^{-1} \left(\dfrac{1}{2}\right)\) (c) \(\cos^{-1} (0) \) (d) \( \tan^{-1} (1)\) (e) \(\cos^{-1} (-1)\)
Watch Solution
(a) \( \sin^{-1} (1)\) (b) \(\sin^{-1} \left(\dfrac{1}{2}\right)\) (c) \(\cos^{-1} (0) \) (d) \( \tan^{-1} (1)\) (e) \(\cos^{-1} (-1)\)
Problem 13Inverse Trig
Find the exact value of each expression in radians:
(a) \(\tan^{-1} \left(-\sqrt{3}\right)\) (b) \(\sin^{-1} \left(-\dfrac{1}{2} \right)\) (c) \(\tan^{-1} \left( \dfrac{\sqrt 3}{3} \right)\) (d) \(\cos^{-1} \left(\dfrac{\sqrt{3}}{2}\right)\)
Watch Solution
(a) \(\tan^{-1} \left(-\sqrt{3}\right)\) (b) \(\sin^{-1} \left(-\dfrac{1}{2} \right)\) (c) \(\tan^{-1} \left( \dfrac{\sqrt 3}{3} \right)\) (d) \(\cos^{-1} \left(\dfrac{\sqrt{3}}{2}\right)\)
Problem 14Inverse Trig
Find the exact value of each expression in radians:
(a) \(\sin^{-1} \left(\sin \dfrac{\pi}{5}\right)\) (b) \(\cos^{-1} \left( \cos \dfrac{5\pi}{6} \right)\) (c) \( \sin^{-1} \left( \ tan \dfrac{3\pi}{4} \right)\) (d) \(\tan^{-1} \left(\tan \dfrac{\pi}{7} \right)\)
Watch Solution
(a) \(\sin^{-1} \left(\sin \dfrac{\pi}{5}\right)\) (b) \(\cos^{-1} \left( \cos \dfrac{5\pi}{6} \right)\) (c) \( \sin^{-1} \left( \ tan \dfrac{3\pi}{4} \right)\) (d) \(\tan^{-1} \left(\tan \dfrac{\pi}{7} \right)\)
Problem 15Equations
Solve each equation on the interval \( 0 \leq \theta < 2\pi\):
(a) \(1-\cos \theta = \frac{1}{2} \) (b) \( 2\sin \theta + \sqrt 3 = 0 \) (c) \(2 \cos \theta - \sqrt {2} = 0 \) (d) \(\sqrt{3} \tan \theta + 3 = 0 \)
Watch Solution
(a) \(1-\cos \theta = \frac{1}{2} \) (b) \( 2\sin \theta + \sqrt 3 = 0 \) (c) \(2 \cos \theta - \sqrt {2} = 0 \) (d) \(\sqrt{3} \tan \theta + 3 = 0 \)
Problem 16Equations
Solve each equation on the interval \( 0 \leq \theta < 2\pi\):
(a) \(4\cos^2 \theta - 3 = 0 \) (b) \( 2\sin^2 \theta - 1 = \sin \theta\)
Watch Solution
(a) \(4\cos^2 \theta - 3 = 0 \) (b) \( 2\sin^2 \theta - 1 = \sin \theta\)