Question

Point A lies on the circle and has an x-coordinate of –3.


Which value could be the y-coordinate for point A?


2.5

2.8

Answer 1

I don't have the circle's equation or picture — can you post that? I need the center and radius (or the circle equation) to test x = −3.

How to check once you give the circle:
1. Substitute x = −3 into the circle's equation (or set the distance from (−3,y) to the center equal to the radius).
2. Solve for y. That will give 0, 1 or 2 possible y-values.
3. See which of the given choices (2.5 or 2.8) matches one of those solutions (allowing for rounding).

Example: if the circle is x^2 + y^2 = 13, substitute (−3)^2 + y^2 = 13 → 9 + y^2 = 13 → y^2 = 4 → y = ±2, so neither 2.5 nor 2.8 would be on that circle.

Send the circle equation or image and I’ll check which choice is correct.