Question

The point $P = (1, 2, 3)$ is reflected in the $xy$ -plane, then its image $Q$ is rotated by $180^\circ$ about the $x$ -axis to produce $R,$ and finally, $R$ is translated by $5$ units in the positive $y$ direction to produce $S.$ What are the coordinates of $S?$

$(1, 7, -3)$

$(-1, 7, -3)$

$(-1, -2, 8)$

$(-1, 3, 3)$

$(1, 3, 3)$

Answer: E

Concepts:transformation 3D geometry coordinate geometry

Difficulty rating: 1390

Solution:

Reflecting $(1, 2, 3)$ in the $xy$ -plane gives $Q = (1, 2, -3).$

Rotating $180^\circ$ about the $x$ -axis negates $y$ and $z,$ giving $R = (1, -2, 3).$

Translating $5$ units in the positive $y$ direction gives $S = (1, 3, 3).$

Thus, the correct answer is E.

2000 AMC 12 Problem 10

Answer: E

Difficulty rating: 1390

Solution:

Problem 10 in Other Years