This week’s topic is: Distance, Midpoint, and Slope.
Q: For what value(s) of x is the point (x,4) exactly 5 units away from the point (6,8)?
Answer: 3 or 9
Solution by hand:
Use the distance formula:
Solution using my TI-84 Plus program DISTANCE:
Draw a picture:
Guess that x=2, maybe. It’s probably an integer if this is an SAT problem. Use the answer choices if available.
The distance is 5.66. It’s too big – you wanted it to be 5 – so move the point a little closer to the middle.
The distance is exactly 5. Perfect. (There’s also another possible answer, x=9. If you have multiple choice answers, you will see 3 and 9 as a choice, so try both and see that they both work. For a grid-in SAT problem, you would only have to find one answer anyway.) :