## Trigonometry (11th Edition) Clone

$r = 4~cos~2\theta$ This graph is a rose. We can see this graph below:
$r = 4~cos~2\theta$ When $\theta = 0^{\circ}$, then $r = 4~cos~0^{\circ} = 4$ When $\theta = 15^{\circ}$, then $r = 4~cos~30^{\circ} = 3.46$ When $\theta = 30^{\circ}$, then $r = 4~cos~60^{\circ} = 2$ When $\theta = 45^{\circ}$, then $r = 4~cos~90^{\circ} = 0$ When $\theta = 60^{\circ}$, then $r = 4~cos~120^{\circ} = -2$ When $\theta = 75^{\circ}$, then $r = 4~cos~150^{\circ} = -3.46$ When $\theta = 90^{\circ}$, then $r = 4~cos~180^{\circ} = -4$ When $\theta = 120^{\circ}$, then $r = 4~cos~240^{\circ} = -2$ When $\theta = 135^{\circ}$, then $r = 4~cos~270^{\circ} = 0$ When $\theta = 150^{\circ}$, then $r = 4~cos~300^{\circ} = 2$ When $\theta = 180^{\circ}$, then $r = 4~cos~360^{\circ} = 4$ When $\theta = 210^{\circ}$, then $r = 4~cos~420^{\circ} = 2$ When $\theta = 240^{\circ}$, then $r = 4~cos~480^{\circ} = -2$ When $\theta = 270^{\circ}$, then $r = 4~cos~540^{\circ} = -4$ When $\theta = 300^{\circ}$, then $r = 4~cos~600^{\circ} = -2$ When $\theta = 330^{\circ}$, then $r = 4~cos~660^{\circ} = 2$ This graph is a rose. We can see this graph below: