What is the arclength of the polar curve f(θ)=sin(3θ)4cot6θ over θ[0,π4]?

1 Answer
Nov 21, 2016

The arclength is infinite.

Explanation:

From the reference Arc Length with Polar Coordinates

L=βα(r(θ))2+(dr(θ)dθ)2dθ

Given: r(θ)=sin(3θ)4cot(6θ),α=0andβ=π4

dr(θ)dθ=3cos(3θ)+24csc2(6θ)

Substituting into the integral:

L=π40(sin(3θ)4cot(6θ))2+(3cos(3θ)+24csc2(6θ))2dθ

This integral does not converge.