Sketch the curve $\displaystyle r = 2cos4\theta$

Attempt:

when $\displaystyle \theta$ = 0, r = 2

when $\displaystyle \theta$ = $\displaystyle \frac{\pi}{6}$, r = -1

when $\displaystyle \theta$ = $\displaystyle \frac{\pi}{4}$, r = -2

The graph I got was a circle (not ment to look like an ellipse in the drawing), but the correct answer was a flower