Splitting up the interval of integration into 
subintervals gives the partition
![\left[0,\dfrac1n\right],\left[\dfrac1n,\dfrac2n\right],\ldots,\left[\dfrac{n-1}n,1\right]](https://tex.z-dn.net/?f=%5Cleft%5B0%2C%5Cdfrac1n%5Cright%5D%2C%5Cleft%5B%5Cdfrac1n%2C%5Cdfrac2n%5Cright%5D%2C%5Cldots%2C%5Cleft%5B%5Cdfrac%7Bn-1%7Dn%2C1%5Cright%5D)
Each subinterval has length 
. The right endpoints of each subinterval follow the sequence
with 
. Then the left-endpoint Riemann sum that approximates the definite integral is
and taking the limit as 
gives the area exactly. We have
Answer: 180 miles x 3 hours = 540
540/2 = 270
270 is the average speed
Step-by-step explanation:
we have
----> inequality A
The solution of the inequality A is the interval ------> [-1,∞)
-------> inequality B
The solution of the inequality B is the interval ------> (-∞,7]
The solution of the compound inequality is
[-1,∞) ∩ (-∞,7]=[-1,7]
therefore
the answer in the attached figure
Answer:
400 lb of salt
Step-by-step explanation:
Let us assume the water flows into the rank for x minutes.
There is an initial of 1000 gallons of water in the tank and water flows in through one pipe at 4 gal/min and through another pipe at 6 gal/min. In x minute, the amount of water in the tank = 1000 + 4x + 6x = 1000 + 10x
Water flows out at 5 gal/min, therefore in x minute the amount of water in the tank = 1000 + 10x - 5x = 1000 + 5x
The tank begins to overflow when it is full (has reached 1500 gallons). Therefore:
1500 = 1000 + 5x
5x = 1500 - 1000
5x = 500
x = 100 minutes.
1/2 lb salt per gallon flows into the tank at 4 gal/min and 1/3 lb of salt is flowing in at 6 gal/min, in 100 min the amount of salt that entered the tank = 4 gal/min × 100 min × 1/2 lb/gal + 6 gal/min × 100 min × 1/3 lb/gal= 400 lb
Therefore the amount of salt is in the tank when it is about to overflow = 400 lb of salt
