# POLQ 3 | Lesson 4 | Solution (Finding the Equation of a Circle)

Solutions:

The equation of the circle is $$(x – 0)^2 + (y – 0)^2 = 16$$ where the center of the circle is $$(0,0)$$ and the radius of 4 squared is 16.

One point is at $$(1, d)$$ . Substituting 1 in for x, the equation is $$(-1)2 + y^2 = 16$$     $$y^2 = 15$$ or     $$y = \sqrt{15}$$

The point is $$(1,\sqrt{15})$$