Difference between revisions of "2007 AMC 12A Problems/Problem 17"
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Revision as of 20:31, 3 July 2013
Problem
Suppose that and
. What is
?
Solution
We can make use the of the Pythagorean identities: square both equations and add them up:



This is just the cosine difference identity, which simplifies to
See also
2007 AMC 12A (Problems • Answer Key • Resources) | |
Preceded by Problem 16 |
Followed by Problem 18 |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | |
All AMC 12 Problems and Solutions |
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