MathDB
Putnam 1940 B2

Source: Putnam 1940

February 22, 2022
Putnamgeometry

Problem Statement

A cylindrical hole of radius rr is bored through a cylinder of radiues RR (rRr\leq R) so that the axes intersect at right angles. i) Show that the area of the larger cylinder which is inside the smaller one can be expressed in the form S=8r2011v2(1v2)(1m2v2)  dv,    where    m=rR.S=8r^2\int_{0}^{1} \frac{1-v^{2}}{\sqrt{(1-v^2)(1-m^2 v^2)}}\;dv,\;\; \text{where} \;\; m=\frac{r}{R}. ii) If K=011(1v2)(1m2v2)  dvK=\int_{0}^{1} \frac{1}{\sqrt{(1-v^2)(1-m^2 v^2)}}\;dv and E=011m2v21v2dvE=\int_{0}^{1} \sqrt{\frac{1-m^2 v^2}{1-v^2 }}dv. show that S=8[R2E(R2r2)K].S=8[R^2 E - (R^2 - r^2 )K].