CPM Homework Banner

Home > PC3 > Chapter 2 > Lesson 2.2.1 > Problem 2-48


Sketch each of the following angles in a unit circle. Then state the coordinates of the corresponding point on the unit circle. 


    The reference angle is . What are the cosine and sine of ? When writing your final answer, remember that this angle is in the fourth quadrant.


    1. Draw a unit circle.
    2. Divide the top and bottom halves into quarters.
    3. Put a mark on the unit circle at the quarters going clockwise from .
    4. Make a triangle with the -axis.
    5. Label the lengths of the sides.
    6. Check for the correct signs.
    7. The coordinates are .

    What are the side lengths? Use the Pythogorean Theorem.


     is the same angle as