27 Oct
2020
27 Oct
'20
10:34 a.m.
PS I absent-mindedly wrote the 3-volume instead of the area of the set A(t). Of course the correct formula is vol_2(A(t)) = 4π sin(t)^2. The maximum is still when sin(t) = 1, i.e., when t = π/2. Ah, the joys of aging! —Dan