\fUse sigma notation to write the sum. 2 6 + 1 13 + 1 + + 6 +1 3 3 3Use sigma notation to write the sum. 2 N 7 - + 7 j=1Use upper and lower sums to approximate the area of the region using the given number of subintervals (of equal width). (Round your answers to three decimal places.) y'=\\/7X upper sum |:| lower sum |:| )' 25 l 2.0 1.5 1.0 0.5 02 0'4 0'6 0'3 170 Use the Midpoint Rule with n = 4 to approximate the area of the region bounded by the graph of the function and the X-axis over the given interval. f(x) = x2 + 5, {0, 2] :1