Find the arc length of the curve defined by r=θ2r = \theta^2r=θ2 for 0≤θ≤50 \leq \theta \leq \sqrt{5}0≤θ≤5.
16(2121−8)\frac{1}{6}(21\sqrt{21} - 8)61(2121−8)
13(2121−1)\frac{1}{3}(21\sqrt{21} - 1)31(2121−1)
23(55−1)\frac{2}{3}(5\sqrt{5} - 1)32(55−1)
525\frac{5}{2}\sqrt{5}255