Problem:
A ship travels from point to point along a semicircular path, centered at Island . Then it travels along a straight path from to . Which of these graphs best shows the ship's distance from Island as it moves along its course?

Answer Choices:
A.





Solution:
All points along the semicircular part of the course are the same distance from , so the first part of the graph is a horizontal line. As the ship moves from to , its distance from decreases, then it increases as the ship moves from to . Only graph has these features.
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Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions