Difference between revisions of "2024 AMC 10A Problems/Problem 13"
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Examine | Examine | ||
+ | == Solution 1 == | ||
+ | Label the transformations as follows: | ||
+ | |||
+ | • a translation 2 units to the right (W) | ||
+ | |||
+ | • a 90°- rotation counterclockwise about the origin (X) | ||
+ | |||
+ | • a reflection across the 𝑥-axis (Y) | ||
+ | |||
+ | • a dilation centered at the origin with scale factor 2 (Z) | ||
+ | |||
+ | Now, examine each possible pair of transformations with the point <math>(1,0)</math> | ||
+ | |||
+ | <math>1. W</math> and <math>X</math>. Going <math>W\rightarrow X</math> ends with the point <math>(0,3)</math>. Going <math>X\rightarrow W</math> ends in the point <math>(1,2)</math>, so this pair does not work | ||
+ | |||
+ | $2. | ||
==See also== | ==See also== | ||
{{AMC10 box|year=2024|ab=A|num-b=12|num-a=14}} | {{AMC10 box|year=2024|ab=A|num-b=12|num-a=14}} | ||
{{MAA Notice}} | {{MAA Notice}} |
Revision as of 17:17, 8 November 2024
Contents
[hide]Problem
Two transformations are said to commute if applying the first followed by the second gives the same result as applying the second followed by the first. Consider these four transformations of the coordinate plane:
• a translation 2 units to the right,
• a 90°- rotation counterclockwise about the origin,
• a reflection across the 𝑥-axis, and
• a dilation centered at the origin with scale factor 2 .
Of the 6 pairs of distinct transformations from this list, how many commute?
Solution 1
Examine
Solution 1
Label the transformations as follows:
• a translation 2 units to the right (W)
• a 90°- rotation counterclockwise about the origin (X)
• a reflection across the 𝑥-axis (Y)
• a dilation centered at the origin with scale factor 2 (Z)
Now, examine each possible pair of transformations with the point
and . Going ends with the point . Going ends in the point , so this pair does not work
$2.
See also
2024 AMC 10A (Problems • Answer Key • Resources) | ||
Preceded by Problem 12 |
Followed by Problem 14 | |
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 10 Problems and Solutions |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.