AP Calculus BC

Advanced Placement Calculus BC including series, parametric equations, and polar functions.

Advanced Topics

Polar Coordinates and Graphs

Going Beyond \( x \) and \( y \)

Polar coordinates describe points by how far they are from the origin (\( r \)) and at what angle (\( \theta \)).

  • Instead of \( (x, y) \), use \( (r, \theta) \).
  • Some curves are easier in polar form, like spirals or roses.

Calculus in Polar Form

  • Area inside a polar curve: \( A = \frac{1}{2} \int_{\alpha}^{\beta} [r(\theta)]^2 d\theta \).
  • Find slopes and lengths of polar curves.

Cool Connections

Polar graphs appear in radar, biology (shells), and engineering (antenna patterns).

Examples

  • A cardioid: \( r = 1 + \cos \theta \).

  • Rose curve: \( r = 2 \sin 3\theta \).

In a Nutshell

Polar coordinates help us describe curves and shapes that are tricky in regular graphs.