A precision-engineered acoustic horn is modeled as a solid of revolution. The internal profile of the horn is defined by the curve C C\,C with equation
y=2x+xxarctan(x) y = \frac{2}{\sqrt{\sqrt{x} + x\sqrt{x}} \arctan(\sqrt{x})} y=x+xxarctan(x)2for 13≤x≤1\frac{1}{3} \le x \le 131≤x≤1. The region RRR is bounded by the curve CCC, the xxx-axis, and the vertical lines x=13x = \frac{1}{3}x=31 and x=1x = 1x=1.
The internal volume V V\,V of the horn is formed by rotating the region RRR through 360∘ 360^\circ\,360∘ about the xxx-axis.
Using the substitution tanu=x\tan u = \sqrt{x}tanu=x,
show that the volume VVV is given by
k∫ab1u2 du k \int_{a}^{b} \frac{1}{u^2} \, du k∫abu21duwhere k,ak, ak,a and bbb are constants to be found.
Hence, using algebraic integration, find the exact value of VVV.