### Home > PC > Chapter 4 > Lesson 4.3.1 > Problem4-128

4-128.

Find the exact value of each of the following trig expressions.

1. sin $\frac { 5 \pi } { 3 }$

1. Plot the point on a unit circle.
2. Find the sides of this special triangle.
3. Be careful of the signs!
4. Write the answer.

1. cos $\frac { 33 \pi } { 4 }$

$\frac{32\pi}{4}$ bring  the point back to $(1,0)$.

1. cot $( - \frac { \pi } { 6 } )$

Wrap clockwise because of the negative sign.

1. sec $\frac { 3 \pi } { 2 }$

Since the sec\theta; is $\frac{1}{\text{cos}\theta}$, this would be undefined because the $\operatorname{cos}=0$ at $\frac{3\pi}{2}$.