<aside>
🐡 Given a point $P$ in the plane with Cartesian coordiates $(x,y)$and polar coordinates $(r, \theta)$:
$x = r\cos \theta$ and $y = r\sin \theta$
$r^2=x^2+y^2$ and $\tan \theta = \frac{y}{x}$
</aside>
Plotting a Curve in Polar Coordinates
- Create a table with $\theta$ and $r$
- Create list of values for $\theta$
- Use $\theta$ to calculate each value for $r$
- Plot each ordered pair $(r, \theta)$ on the coordinate axes
- Connect the points and look for a pattern
- Look for symmetry!
Symmetry of Polar Equations
- If $f(\theta) = f(-\theta)$
- Symmetric about “x-axis”
- If $f(\pi -\theta) = f(\theta)$
- Symmetric about “y-axis”
- If $f(\theta + \pi) = -f(\theta)$
- Symmetric about origin
Common Curves