Here is an exercise to exhibit a couple of quirks of high dimensional solids. (Not as directly related to first year calculus courses as most things in this thread, but it is first year level stuff, and it is in the calculus/analysis ballpark.)
a) By generalising MX2 methods of volume calculation, find an expression for the volume of the n-dimensional ball of radius r in terms of the Gamma function
b) How does this quantity behave asymptotically as n->inf? Interpret this as a comparative statement about n-dimensional balls and n-dimensional cubes.
c) What happens to |B(r-d)|/|B(r)| as n-> inf? Here B(r) denotes the n-dimensional ball of radius r, and d < r is fixed. Interpret this result as a statement about the asymptotic concentration of mass in high dimensional balls.
d) Show that the the limiting behaviour in (c) can occur even if d(n) depends on n and monotonically decreases to zero. For which power rates of decay d(n)=n^(-p) will this happen?
e) Repeat c) and d), this time for strips about the equator. That is, what can we say about the limiting behaviour of |{x in B(r): |x_n| < d}|/|B(r)|? What does this say about the asymptotic concentration of mass in high dimensional balls? Can we take d(n)->0 and still have the same behaviour? At what power rate can d tend to zero with us having the same limiting behaviour?