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Home > PC > Chapter 4 > Lesson 4.1.1 > Problem 4-7


Sketch each of the following angles onto a unit circle then find the coordinates of the angle.

  1. 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. 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.

  1.  is the same angle as