In lecture we did an amortized analysis of the AddLast operation on a list represented by a dynamic array. We did this under the assumption that the underlying static array is replaced by one that is two times as long each time it fills up. We found that if: bullet a is the cost of an AddLast operation when array doubling is not needed, and bullet r is the per-element cost of copying the elements of an array into one that is twice as long then the average cost of an AddLast operation is a + 2r