Stage: 4 Challenge Level: 
Watch the animation.
Can you explain what is happening?
What do you notice about the numbers that appear towards the end of the sequence?
Can you explain how they vary and why?
What would happen if the dot kept going around the circle increasing the angle beyond 360 degrees?
Full Screen Version
This text is usually replaced by the Flash movie.
After this you might like to look at the problem Trigonometric Protractor.
Animations. Cosine. Similarity. Graphs. Complex numbers. alphas. Trigonometric identities. Long problems. Tangent. Sine.
Published May 2008.
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