40 likes | 227 Views
# of cars = (82 + 4 sin(t/2)) dt. 30. 0. Part (a). To find the total number of cars, we need to integrate. 2474.077. Keep in mind that you must be in RADIANS. 2474 cars. Part (b). Since F(t) is the traffic flow, then F’(t) would be the RATE OF CHANGE of the traffic flow.
E N D
# of cars = (82 + 4 sin(t/2)) dt 30 0 Part (a) To find the total number of cars, we need to integrate. 2474.077 Keep in mind that you must be in RADIANS. 2474 cars
Part (b) Since F(t) is the traffic flow, then F’(t) would be the RATE OF CHANGE of the traffic flow. We were asked if the traffic flow was increasing or decreasing at t=7. For this, we’ll need the derivative. F’(t) = 2 cos (t/2) -1.872 or -1.873 Since F’(7) is negative, the traffic flow is decreasing at t=7.
The AP Test graders don’t expect you to show the work for this integration (u-subs, etc). That just wastes your valuable testing time. Instead, simply show them your integral and then evaluate it using the graphing calculator. Average value = (82 + 4 sin(t/2)) dt 1 15 15-10 10 Part (c) NOTE: Part (c) uses a formula from Calculus, while Part (d) is nothing more than an Algebra 1 problem. Average value = 81.899 cars/minute
F(15) – F(10) 15 - 10 85.752 – 78.164 15 - 10 Part (d) The AVERAGE RATE OF CHANGE is not Calculus. It’s the slope formula from Algebra 1. Keep in mind that you must be in RADIANS. AVG. RATEOF CHANGE = 1.517 or 1.518 cars/min2