Chapter 8 - Complex Numbers, Polar Equations, and Parametric Equations - Section 8.5 Polar Equations and Graphs - 8.5 Exercises - Page 395: 72

First we can find the angle $\theta$ by rotating counter-clockwise from the positive x-axis. We can then draw a line with a magnitude of $\vert r \vert$, starting from the origin and pointing in the opposite direction from the angle $\theta$.

$(r,\theta)$ is a point in polar coordinates and $r \lt 0$ First we can find the angle $\theta$ by rotating counter-clockwise from the positive x-axis. We can then draw a line with a magnitude of $\vert r \vert$, starting from the origin and pointing in the opposite direction from the angle $\theta$. Note that we must draw the line in the opposite direction from angle $\theta$ because $r \lt 0$