In the figure above, the circle is centered at the origin and passes through point P. Which of the following points does it also pass through?
(A) (3, 3)
(B) (-2√2, -1)
(C) (2, 6)
(D) (1.5, 1.3)
(E) (-3, 4)
Some SAT math questions are designed to look like they require all kinds of calculations in order to solve them when in reality calculations are not necessary at all. This question is a perfect example. Do we really need to do any calculating here? Well, let’s see. We know that the center of the circle is (0, 0). We also know that the circle passes through point P, (0, -3). The circle has a radius of 3. Now look at the choices. Could (3, 3) possibly be correct? No, it would clearly fall outside of the circle. How about (2, 6)? No way!! (1.5, 1.3)? No. That would be inside the circle. And (-3, 4)? That would be outside of the circle. By elimination, (B) must be correct.
If the incorrect choices had been less obvious, then the method here would have been to use the distance formula to figure out which ordered pair would be 3 units away from the origin. If you try that, you’ll find that only (B) will work. The answer is (B).
source: novapress.net
