2010 Question 1 (a) 142.275 cubic feet (must show integral for full credit) (b) -59.583 cubic feet per hour 0 , 0≤𝑡≤6 (c) ℎ(𝑡) = { 125(𝑡 − 6) , 6 < 𝑡 ≤ 7 125 + 108(𝑡 − 7), 7 < 𝑡 ≤ 9 (d) 26.335 cubic feet (must show integral and h(9) for full credit) Question 2 (a) 4 hundred entries per hour (b) Trapezoidal sum: 10.688; the meaning is the average number of hundreds of entries in the box between noon and 8PM. (c) 7 hundred entries (must show integral for full credit) (d) Entries are being processed most quickly at time t = 12 (must set P’(t) = 0 and identify all four possible candidates – 8, 9.184, 10.816, 12 – for full credit) Question 3 (a) 3200 people (must show integral for full credit) (b) Increasing because r(t) > 800 for 2 < t < 3. (c) t = 3; 1500 people waiting in line 𝑡 (d) 0 = 700 + ∫0 𝑟(𝑠)𝑑𝑠 − 800𝑡 Question 4 (a) 18 (must show integral and antiderivative for full credit) 2 9 (b) 𝜋 ∫0 ((7 − 2√𝑥) − (7 − 6)2 ) 𝑑𝑥 6 3 4 𝑦 𝑑𝑦 16 (c) ∫0 Question 5 (a) 𝑔(3) = 13 + 2 𝜋; 𝑔(−2) = 5 − 𝜋 (b) The graph of y = g(x) has points of inflection at x = 0, x = 2, and x = 3 because g’ changes from increasing to decreasing at x = 0 and x = 3, and g’ changes from decreasing to increasing at x = 2. (c) ℎ′ (𝑥) = 𝑔′ (𝑥) − 𝑥 ; Critical points are 𝑥 = √2 (relative max) and 𝑥 = 3 (neither a minimum nor a maximum). Question 6 (a) 𝑓 ′ (1) = 8; 𝑦 = 2 + 8(𝑥 − 1) (b) 𝑓(1.1) ≈ 2.8; Because f(x) is concave up, the approximation 2.8 is less than f(1.1). (c) 𝑓(𝑥) = 2 √5−4𝑥 2 2011 (Form B) Question 1 (a) (b) (c) (d) 171.813 mm (must show integral for full credit) 2.864 mm/day 𝑉(𝑡) = 100𝜋𝑆(𝑡); 𝑉 ′ (7) = 602.218 cubic mm per day 𝐷(0) = −0.675 < 0 and 𝐷(60) = 69.3773 > 0; Because D is continuous, the IVT implies that there is a time t, 0 < t < 60, at which D(t) = 0. At this time, the heights of water in the two cans are changing at the same rate. Question 2 (a) The left-hand and right-hand limits are not equal, so r is not continuous at t = 5. (b) 258.053 (must show integral for full credit) (c) 𝑟 ′ (3) = 50; The rate at which water is draining out of the tank at time t = 3 hours is increasing at 50 liters per hour squared. 𝐴 (d) 12,000 − ∫0 𝑟(𝑡)𝑑𝑡 = 9000 Question 3 (a) 22 3 (must show integral for full credit) 2 (b) Volume = ∫0 2𝑦(6 − 𝑦 − 𝑦 2 )𝑑𝑦 (c) 𝑓 ′ (𝑥) = 2 1 √𝑥 ;2 1 √𝑥 1 1 1 = 1 → 𝑥 = 4 ; The point P has coordinates (4 , 2). Question 4 (a) x = 4; It is a relative maximum. 2(𝑥−6) ; 𝑥4 −2 −1 (b) 𝑓 ′′ (𝑥) = (c) 3 − 2𝑥 +𝑥 The graph of f is concave down on the interval 0 < x < 6. (must show integral and antiderivative for full credit) Question 5 (a) (b) (c) (d) 0.03 meters/sec2 The total distance that Ben rides from t = 0 to t = 60 is 139 meters. Yes, the Mean Value Theorem implies there must be a time where v(t) = 2. 1.5 meters per second Question 6 (a) 6π2 (must show antiderivative for full credit) (b) x = 0 and x = π 𝜋 (c) ℎ′ (𝑥) = 𝑔(3𝑥) ∙ 3 ; ℎ′ (− 3 ) = 3𝜋