1. The problem statement, all variables and given/known data Find the arc length of one of the leaves of the polar curve r= 6 cos 6θ. 2. Relevant equations L = ∫sqrt(r^2 + (dr/dθ)^2) dθ (I use twice that since the length from 0 to π/12 is only half the petal) 3. The attempt at a solution I seem to get an integral that can't be solved: L = 2∫sqrt((6 cos 6θ)^2 + (-36 sin 6θ)^2) dθ = 2∫sqrt(36 cos^2 6θ + 1296 sin^2 6θ) dθ I simplify the cos^2 and sin^2 to get L = 2∫sqrt(36 + 1260 sin^6θ) dθ = 12∫sqrt(1+35 sin^2 6θ) dθ but that's where I'm stuck. I have no idea how to do that integral. Any help would be sincerely appreciated!