If the circle has a radius of 3 units and the center lies on the y-axis, which set of values of A, B, C, D, and E might correspond to the circle in general form?
The general form for a conic section is:
For a circle we know that
The phrase; "the center lies on the y-axis" tells us that the x coordinate of the center is 0 and, therefore,
We can infer nothing about E, except
Also, the phrase; "the circle has a radius of 3 units" tells us that