2013-78.md

course	course_year	question_number	tags	title	year
Variational Principles	IB	78	IB 2013 Variational Principles	Paper 3, Section I, A	2013

A cylindrical drinking cup has thin curved sides with density $\rho$ per unit area, and a disk-shaped base with density $k \rho$ per unit area. The cup has capacity to hold a fixed volume $V$ of liquid. Use the method of Lagrange multipliers to find the minimum mass of the cup.