# [Not Homework!] Polar Equation Problem Involved Tangents

1. Apr 15, 2012

### suporia

Not homework, just trying to learn how to solve this problem for an exam.

1. The problem statement, all variables and given/known data

https://dl.dropbox.com/u/23889576/Screenshots/10.png [Broken]

2. Relevant equations

$\int_{a}^{b} \sqrt { (\frac{dr}{dθ})^2 + r^2 }\, dθ$

3. The attempt at a solution

Had much difficulty, could not even derive the original derivative function for this problem.

Last edited by a moderator: May 5, 2017
2. Apr 15, 2012

### tiny-tim

welcome to pf!

hi suporia! welcome to pf!

the figure is symmetric, so when one bug is at (r,θ), the next is at (r,θ+π/2) …

does that help?