Difference between revisions of "2008 AIME II Problems/Problem 1"
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Revision as of 21:25, 24 November 2019
Contents
Problem
Let
, where the additions and subtractions alternate in pairs. Find the remainder when
is divided by
.
Solution
Rewriting this sequence with more terms, we have
Factoring this expression yields
Next, we get
Then,

Dividing
by
yields a remainder of
.
Solution 2
Since we want the remainder when
is divided by
, we may ignore the
term. Then, applying the difference of squares factorization to consecutive terms,

See also
| 2008 AIME II (Problems • Answer Key • Resources) | ||
| Preceded by First Question |
Followed by Problem 2 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 | ||
| All AIME Problems and Solutions | ||
These problems are copyrighted © by the Mathematical Association of America, as part of the American Mathematics Competitions.