Chapter 10

A Graphical Approach to Precalculus with Limits · 484 exercises

Problem 37

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$\tan \theta+\cot \theta=0$$

7 step solution

Problem 37

Write expression as a single trigonometric function or a power of a trigonometric function. (You may wish to use a graph to support your result.) $$\frac{\sin ^{2} x}{\cos ^{2} x}+\sin x \csc x$$

4 step solution

Problem 37

Use identities to write each expression as a function with \(x\) as the only argument. $$\cos \left(135^{\circ}-x\right)$$

4 step solution

Problem 38

Solve each equation ( \(x\) in radians and \(\theta\) in degrees) for all exact solutions where appropriate. Round approximale values in radians to four decimal places and approximate values in degrees to the nearest tenth. Write answers using the least possible nonnegative angle measures. $$\sin \theta-\sin 2 \theta=0$$

6 step solution

Problem 38

Give the degree measure of \(\theta,\) if it exists. Do not use a calculator. $$\theta=\arcsin \left(-\frac{\sqrt{2}}{2}\right)$$

4 step solution

Problem 38

Use a half-number (or angle) identity to find an expression for the exact value for each trigonometric function. $$\cos 67.5^{\circ}$$

5 step solution

Problem 38

Write expression as a single trigonometric function or a power of a trigonometric function. (You may wish to use a graph to support your result.) $$\frac{1}{\tan ^{2} \alpha}+\cot \alpha \tan \alpha$$

4 step solution

Problem 38

Use identities to write each expression as a function with \(x\) as the only argument. $$\sin \left(45^{\circ}+x\right)$$

5 step solution

Problem 39

Use a graphical method to solve each equation over the interval \([0,2 \pi) .\) Round values to the nearest thousandth. $$\sin x+\sin 3 x=\cos x$$

5 step solution

Problem 39

Give the degree measure of \(\theta,\) if it exists. Do not use a calculator. $$\theta=\cot ^{-1}\left(-\frac{\sqrt{3}}{3}\right)$$

5 step solution

Problem 39

Use a half-number (or angle) identity to find an expression for the exact value for each trigonometric function. $$\sin 67.5^{\circ}$$

4 step solution

Problem 39

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$9 \sin ^{2} \theta-6 \sin \theta=1$$

7 step solution

Problem 39

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\cot \theta \sin \theta$$

2 step solution

Problem 39

Use identities to write each expression as a function with \(x\) as the only argument. $$\tan \left(45^{\circ}+x\right)$$

3 step solution

Problem 40

Use a graphical method to solve each equation over the interval \([0,2 \pi) .\) Round values to the nearest thousandth. $$\sin 3 x-\sin x=0$$

7 step solution

Problem 40

Give the degree measure of \(\theta,\) if it exists. Do not use a calculator. $$\theta=\sec ^{-1}(-2)$$

4 step solution

Problem 40

Use a half-number (or angle) identity to find an expression for the exact value for each trigonometric function. $$\tan 195^{\circ}$$

5 step solution

Problem 40

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$4 \cos ^{2} \theta+4 \cos \theta=1$$

8 step solution

Problem 40

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\sec \theta \cot \theta \sin \theta$$

2 step solution

Problem 40

Use identities to write each expression as a function with \(x\) as the only argument. $$\tan (\pi+x)$$

3 step solution

Problem 41

Use a graphical method to solve each equation over the interval \([0,2 \pi) .\) Round values to the nearest thousandth. $$\cos 2 x+\cos x=0$$

5 step solution

Problem 41

Give the degree measure of \(\theta,\) if it exists. Do not use a calculator. $$\theta=\csc ^{-1}(-2)$$

5 step solution

Problem 41

Use a half-number identity to find an expression for the exact value for each function, given the information about \(x\). $$\cos \frac{x}{2}, \text { given } \cos x=\frac{1}{4} \text { and } 0 < x < \frac{\pi}{2}$$

4 step solution

Problem 41

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$\tan ^{2} \theta+4 \tan \theta+2=0$$

7 step solution

Problem 41

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\cos \theta \csc \theta$$

5 step solution

Problem 42

Use a graphical method to solve each equation over the interval \([0,2 \pi) .\) Round values to the nearest thousandth. $$\sin 4 x+\sin 2 x=2 \cos x$$

5 step solution

Problem 42

Give the degree measure of \(\theta,\) if it exists. Do not use a calculator. $$\theta=\csc ^{-1}(-1)$$

4 step solution

Problem 42

Use a half-number identity to find an expression for the exact value for each function, given the information about \(x\). $$\sin \frac{x}{2}, \text { given } \cos x=-\frac{5}{8} \text { and } \frac{\pi}{2} < x < \pi$$

6 step solution

Problem 42

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$3 \cot ^{2} \theta-3 \cot \theta-1=0$$

8 step solution

Problem 42

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\frac{\sec \theta}{\csc \theta}$$

3 step solution

Problem 43

Use a graphical method to solve each equation over the interval \([0,2 \pi) .\) Round values to the nearest thousandth. $$\cos \frac{x}{2}=2 \sin 2 x$$

5 step solution

Problem 43

Use a half-number identity to find an expression for the exact value for each function, given the information about \(x\). $$\tan \frac{x}{2}, \text { given } \sin x=\frac{3}{5} \text { and } \frac{\pi}{2} < x < \pi$$

4 step solution

Problem 43

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$\sin ^{2} \theta-2 \sin \theta+3=0$$

5 step solution

Problem 43

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\frac{\cot ^{2} \theta}{\csc ^{2} \theta}$$

4 step solution

Problem 44

Use a graphical method to solve each equation over the interval \([0,2 \pi) .\) Round values to the nearest thousandth. $$\sin \frac{x}{2}+\cos 3 x=0$$

5 step solution

Problem 44

Use identities to write each expression as a finction with \(x\) as the only argument. $$\tan \left(x+\frac{7 \pi}{4}\right)$$

4 step solution

Problem 44

Use a half-number identity to find an expression for the exact value for each function, given the information about \(x\). $$\cos \frac{x}{2}, \text { given } \sin x=-\frac{4}{5} \text { and } \frac{3 \pi}{2} < x < 2 \pi$$

5 step solution

Problem 44

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$2 \cos ^{2} \theta+2 \cos \theta+1=0$$

5 step solution

Problem 44

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\frac{\tan ^{2} \theta}{\sec ^{2} \theta}$$

2 step solution

Problem 45

Use a half-number identity to find an expression for the exact value for each function, given the information about \(x\). $$\tan \frac{x}{2}, \text { given } \tan x=\frac{\sqrt{7}}{3} \text { and } \pi < x < \frac{3 \pi}{2}$$

6 step solution

Problem 45

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$\cot \theta+2 \csc \theta=3$$

5 step solution

Problem 45

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$1-\cos ^{2} \theta$$

3 step solution

Problem 46

Give the degree measure of \(\theta,\) if it exists. Do not use a calculator. $$\theta=\csc ^{-1} \frac{1}{3}$$

3 step solution

Problem 46

Use a half-number identity to find an expression for the exact value for each function, given the information about \(x\). $$\tan \frac{x}{2}, \text { given } \tan x=-\frac{\sqrt{5}}{2} \text { and } \frac{\pi}{2} < x < \pi$$

6 step solution

Problem 46

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$2 \sin \theta=1-2 \cos \theta$$

7 step solution

Problem 46

Write expression in terms of sine and cosine, and simplify it. (The final expression does not have to be in terms of sine and cosine.) $$\frac{1}{1+\cot ^{2} \theta}$$

4 step solution

Problem 47

Suppose that A and B are angles in standand position. Use the given information to find (a) \(\sin (A+B)\), (b) \(\sin (A-B)\), (c) \(\tan (A+B)\), (d) \(\tan (A-B)\), (e) the quadrant of \(A+B\), and ( \(f\) ) the quadrant of \(A-B\). Do not use a calculator. $$\cos A=\frac{3}{5}, \sin B=\frac{5}{13}, \quad 0

8 step solution

Problem 47

Use a calculator to give each value of \(\theta\) in decimal degrees. $$\theta=\sin ^{-1}(-0.13349122)$$

4 step solution

Problem 47

$$\tan \frac{x}{2}, \text { given } \tan x=-\frac{\sqrt{5}}{2} \text { and } \frac{\pi}{2}

8 step solution

Problem 47

Solve each equation for solutions over the interval \(\left[0^{\circ}, 360^{\circ}\right) .\) Give solutions to the nearest tenth as appropriate. $$8 \cos ^{2} \theta+18 \cos \theta=5$$

6 step solution

Show/ page