Question

Determine the average rate of fuel consumption for the ninety minute flight.

Answer 1

R(t) = .4t − 20 cos(π t / 45) + 40

Answer 2

I assume the variable t = time of flight and R = average rate. Therefore just substitute t =90 and solve.
R(t) = .4(90) − 20 cos(π (90)/ 45) + 40
R(t) = 56

Answer 3

I thought the same but this is also stated. The rate of fuel consumption, in gallons per minute, recorded during an airplane flight is given by a differentiable function R of time
I should've added it.

Answer 4

Does it ask what measurements the final rate of consumption should be in?

Answer 5

R is supposed to be the rate..... so what about the average rate?

Answer 6

That's weird because I was thinking that maybe we need to graph this and find the average of the graph but it when graphed it gives a straight line so fuel consumption stay the same.

Answer 7

when I graph it I don't have a straight line

Answer 8

Hmm what did you type into graph?

Answer 9

We know for this flight that the time was 90mins so I substituted 't' for 90 in the formula which gives: .4(90) − 20 cos(π (90) / 45) + 40 which is a straight line.. So I'm actually really confused by what they wont you to do here.. Sorry :/

Answer 10

*want

Answer 11

well of course it's going to be a straight line because y is going to equal one thing. I'm thinking that it's 90 plugged into the first derivative.

Answer 12

I just want some conformation

Answer 13

Ok, I'm obviously not the right person to ask :P

Answer 14

that's fine :) you gave me some ideas