4. It can be shown using material from a later section that is given by 0-122 dx (-1)na2n+1 n!2n (2n+1) n=0 for any positive value of a. When a is positive, this series is an alternating series. (a) Approximate e-1 x dx to four decimal places accuracy by using the Alternating Series Test and its remainder theorem. (Be careful to not round intermediate steps.) (b) Using the same number of terms as you used in your sum in part (a), compute the midpoint approximation Mn for the integral L'ob de dx (c) Which approximation is more accurate? This should be determined using just parts (a) and (b).