Consider the number S = 1210. Here is an equivalent way to ex- press the same positive integer: S 25+36+49+64+81+100+121+144+169+ 196+225 Parts (a)-(c) below use summation notation to present this number in three different-looking ways. (a) Find m and n to make S = n : m = n = i=m S (b) Find r and s to make S = (j + 2): r = j=r S= 11 (c) Find f(k) to make S = f(k): f(k) = = k=1