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Section 4.8– Number 6 Describe in words how the unit circle is traced out, including when the particle is moving clockwise and when and where the particle is moving counter clockwise. x = cos t y = sin t Solution: The easiest way to do this is to make a table for t, x and y. t −2π x y 1 0 − 3π 2 −π 0 1 −1 0 − π 0 π 1 0 0 1 2 0 −1 π 3π 2 2π −1 0 0 −1 1 0 2 Plotting the (x, y) ordered pairs, we have y 1 −1 1 x −1 This describes the particle going in a counterclockwise direction for all t, it does not change direction.