Chapter 10 - Parametric Equations and Polar Coordinates - 10.3 Exercises - Page 687: 38

See image below.

First, define r as a function of $\theta$ $ r=f(\theta)=-2\sin\theta$ Then build a table of values for $\theta=0,\pi/6,\pi/3,...$ and for each $\theta$ calculate x coordinate = $ f(\theta)\cdot\cos\theta,\qquad y=f(\theta)\cdot\sin\theta$ Plot the points and join with a smooth curve. (Work done in geogebra.)