Determine a region whose area is equal to the given limit. Do not evaluate the limit. lim n → [infinity] n i = 1 π 4n tan iπ 4n tan(x) on − π 4 , π 4 tan(x) on 0, π 4 x tan(x) on 0, π 4 x tan(x) on − π 4 , π 4 tan(x) on [0, 4π]