### Home > PC3 > Chapter 13 > Lesson 13.1.1 > Problem13-14

13-14.

Write the equation of each conic described below.

1. A circle whose center lies on the line $3x + y = 6$. The circle has a radius of $4$ and is tangent to the $y$-axis.

The $x$-coordinate of the circle must be either $x = 4$ or $x = −4$. Why?

2. A parabola with the focus at $\left(3, 2\right)$ and a directrix of $x = −5$.

This parabola opens to the left. Why?
Sketch the situation to help locate the vertex and determine the value of $c$.

Review the Math Notes box in Lesson 11.1.5.