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Home > PC > Chapter 4 > Lesson 4.1.4 > Problem 4-55


Study the diagram of the unit circle below right, in which VW .  

  1. Find .

    In a unit circle, what is the radius?

  2. Find .

    You have two sides of a right triangle. Find the third side, which is the -coordinate.

  3. α is another angle with the same sine as , but a different cosine. What quadrant is in?

    In Quadrant III, sine and cosine are both negative.
    In which quadrant is sine negative and cosine positive?

  4. is another angle with the same cosine as , but a different sine. What quadrant is in?

    In which quadrant is cosine negative and sine positive.

Unit Circle, with a right triangle in third quadrant, using Point, w, on the circle, horizontal leg on negative, x axis, vertical leg, V W, is labeled 0.62. Central angle, from the positive, x axis, to the radius in third quadrant, labeled theta, with a curved arrow, pointing counter clockwise.