### Home > INT3 > Chapter 12 > Lesson 12.1.3 > Problem12-48

12-48.
1. A circle with its center on the line y = 3x in the first quadrant is tangent to the y‑axis. 12-48 HW eTool (Desmos). Desmos Accessibility Homework Help ✎

1. If the radius is 2, what is the equation of the circle?

2. If the radius is 3, what is the equation of the circle?

What point on the line y = 3x is 2 units from the y-axis?

Use the coordinates of the center and the radius to write an equation in general form.

$(x - 2)^2 + (y - 6)^2 = 4$

See part (a).

$(x - 3)^2 + (y - 9)^2 = 9$

Use the eTool below for help with this problem.
Click on the link at right for the full eTool version: Int3 12-48 HW eTool