So I am going through Spivak's Calculus on Manifolds trying to answer all the problems. I've found a solution set and I'm trying to make sense of one part (Seventh assignment - Solutions#_). In problem no. 4-24 on that page, in the third set of gray boxes of the problem (the limits), I'm not sure what we are taking the limits of here (i.e. what should be on the left hand side). If anyone could help that would be very useful to me.