Using the shell method, the volume is given exactly by the definite integral,

Splitting up the interval [0, 1] into 5 subintervals gives the partition,
[0, 1/5], [1/5, 2/5], [2/5, 3/5], [3/5, 4/5], [4/5, 5]
with left and right endpoints, respectively, for the
-th subinterval


where
. The midpoint of each subinterval is

Then the Riemann sum approximating the integral above is



(compare to the actual value of the integral of about 14.45)
The quotient is : 5x-12+(25)/(x+3)
The remainder is : 25
Answer:
<h2>B. The amount of fuel used was lowest at speeds around 60km/h.</h2>
Step-by-step explanation:
The decreasing part is from (20,13) to (60,6), which gives an average rate of

Then, we have an increasing part from (60,6) to (120,10), which gives an average rate of

Basically, at 60 km/h the fuel used was 6 liters per 100 kilometers. Notice that the other velocities make the car to use more liters per kilometers.
Therefore, the amount of fuel used was lowest at speeds around 60 km/h.
The correct answer is A) 2:3 because 4/6 simplified is 2/3