Difference between revisions of "1984 USAMO Problems/Problem 3"
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Since <math>\theta < \frac{\pi}{2}</math>, then <math>\angle APC + \angle BPD < \pi</math> | Since <math>\theta < \frac{\pi}{2}</math>, then <math>\angle APC + \angle BPD < \pi</math> | ||
− | Smallest value is achieved when point P is above and the remaining points are as close as possible to colinear when <math>\theta>0</math>, then <math>\angle APC + \angle BPD > | + | Smallest value is achieved when point P is above and the remaining points are as close as possible to colinear when <math>\theta > 0</math>, then <math>\angle APC + \angle BPD > 0</math> |
and the inequality for this problem is: | and the inequality for this problem is: |
Latest revision as of 02:26, 21 November 2023
Problem
,
,
,
, and
are five distinct points in space such that
, where
is a given acute angle. Determine the greatest and least values of
.
Solution
Greatest value is achieved when all the points are as close as possible to all being on a plane.
Since , then
Smallest value is achieved when point P is above and the remaining points are as close as possible to colinear when , then
and the inequality for this problem is:
~Tomas Diaz. orders@tomasdiaz.com
Alternate solutions are always welcome. If you have a different, elegant solution to this problem, please add it to this page.
See Also
1984 USAMO (Problems • Resources) | ||
Preceded by Problem 2 |
Followed by Problem 4 | |
1 • 2 • 3 • 4 • 5 | ||
All USAMO Problems and Solutions |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.