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in sonaronn webwork / math111fall-mcginnis / ww 6t-section 4/6 Log Oua ets ww 6T-Section 4: Problem 6 Section 4 6 Previous Problem List Next (1 point) Let t be the time in weeks. At time lems t 0, organic waste is dumped into a pond. The oxygen level in the pond at time t is given by AII+1 12+1 Assume f(0) 1 is the normal level of oxygen. (a) On a separate piece of paper, graph this function. (b) What will happen to the oxygen level in the lake as time goes on? The oxygen level will eventually return to its normal level in the long-run. (c) Approximately how many weeks must pass before the oxygen level returns to 80 % of its normal level? weeks (Round to at least two decimal places.) help (numbers) Note: You can earn partial credit on this problem. Submit Answers Preview My Answers You have attempted this problem 2 times. Your overall recorded score is 50 %. You have unlimited attempts remaining.

Answer 1

Solutions. Let the time in weeks, The onygen revel in the bond at time t is given of f(t)= t- tt1 trel Assume f(to)=1 is the normal level of oxygen. fut! graph of f(t)- ttt! set1 ->t f(1) = 1377 fl-2) = 7 < fl-1). f(-3) = 13 <H1-2). f(1) = 2 +62) = 3 7 / 2 = 411) f(3) = 7 7 f(2) As time t oo. -tti am Im H +-700 t-00 to trel alim 2 (1-12 + 1/ ) (141 ) - 1.- HOM i. As time goes ong flt f lo) 1. mis onyzen revel will eventually return to it normal level in the long run. Given condition, that fit) = 80 flo) ③ & (tx- til) = 21 since the onyzen level first decreases. & Str_5+15= 4 Eve 4 up to 50% at t=1. V-5t+1-0. And then increases t= 5 +425-4 to its normal nevel as time goes on. t= 0.21 on t= 4.79. Thus the escygen lever returns to 80% when t29.79. thers. Answer ix (4.79 weeks.