# Trigonometry Classwork 4-24

Consider the unit circle…

Recall that each central angle measure corresponds to a terminal point, expressed as x- and y-coordinates. For example, the terminal point of 270° is (0,-1). Define a function that models this relationship and graph it in degrees. Then graph it in radians.

After you’ve drawn your graphs, check out the applets here. Are any of them demonstrating the function that you just graphed? What’s the name of that function?

# Trigonometry Homework #6 due 3-23

For each equation below, determine whether it is true for all possible values of the variables or not and explain your answer. Ignore values of the variables for which any term is undefined.

1. $\log \left (\frac{x}{y} \right )= \frac{\log{x}}{\log{y}}$

2. $\log_2 (x-y) = \log_2 x - \log_2 y$

3. $\log_5 \left (\frac{a}{b^2} \right )= \log_5 a - 2 \log_5 b$

4. $\log 2^z = z \log 2$

5. $(\log P)(\log Q)= \log P + \log Q$

6. $\frac{\log a}{\log b}= \log a - \log b$

7. $(\log_2 7)^x =x \log_2 7$

8. $\log_a a^a =a$

9. $\log (x-y) = \frac{\log x}{\log y}$

10. $-\ln \left (\frac{1}{A} \right )=\ln A$

# Electronic Technician solutions

1. $R_3=7000$
2. $R_2=30$
3. $R_4=6000$
4. $R_2=6000$
5. $R_6=40$

# Trig function values of special angles classwork solutions

1. $\frac{-\sqrt{3}}{2}$

2. $\frac{-\sqrt{2}}{2}$

3. undefined

4. $\frac{-9}{2}$

5. $\frac{2}{3}$

# Classwork: Practicing trig function values of special angles

1. Find the exact value of cos-150º

2. Find the exact value of sin315º

3. Find the exact value of cot180º

4. If $\cos\theta=\frac{-2}{3}$ and $\cot\theta=3$ find $\csc\theta$

5. If $\csc\theta=12$ and $\sec\theta=8$ find $\tan\theta$

# Classwork: Using the sine function to investigate triangles

1. What is the area of this triangle?

2. Points A andare separated by a lake. To find the distance between them, a surveyor locates a point C on land such that $\angle CAB=48.6\,^{\circ}$. He also measures CA as 312 ft and CB as 527 ft. Find the distance between A and B.