Question

How do you find the equation of the circle given Radius 3 and Tangent to y-axis at (0,4)?

Answer 1

There is not enough information to uniquely solve this problem. Please see the explanation.

Explanation:

The phrase, "Tangent to the y-axis at `(0,4)`", tells us that the y coordinate of the center is 4. The phrase "given radius 3" tells us that the x coordinate of the center can be either -3 or 3 but there is no way to know which. Therefore, the equation of the circle is either:

`(x - -3)^2 + (y - 4)^2 = 3^2` or `(x - 3)^2 + (y - 4)^2 = 3^2`