Use the \"two pictures\" concept of boxes and the area under a curve (refer to picture below) to estimate the size of the sum S. That is, find two numbers, a lower estimate A and an upper estimate B, such that A Solution Now, as n= 108 , values come out to be: A= 2*(104) - 2 = 19998 and B= 20000. Note: this sum diverges and approaches infinity as n approaches infinity..