Answer:

Step-by-step explanation:
The length of any arc is calculated using the following equation:
s = r*θ
Where s is the length of the arc, r is the radius of the circle and θ is the angle in radians.
So, if we have a Circle O and a centrally angle AOB that measures π/3 radians, the value of the length of arc AB is calculated as:

Where r is the radius of the circle O.
Answer:
25%
Step-by-step explanation:
First find the difference in price= $8-$6 = $2
Now, find percentage decrease in the price of sandwich.
Percentage decrease= (difference in price/ original price) *100
=
*100
=
Percentage decrease=25%
To round off to 10, the difference should range from 5 to 14. If the difference between two numbers is from 5 to 14, they all are rounded to 10.
Example:
(near to 10)



Split up the interval [2, 5] into

equally spaced subintervals, then consider the value of

at the right endpoint of each subinterval.
The length of the interval is

, so the length of each subinterval would be

. This means the first rectangle's height would be taken to be

when

, so that the height is

, and its base would have length

. So the area under

over the first subinterval is

.
Continuing in this fashion, the area under

over the

th subinterval is approximated by

, and so the Riemann approximation to the definite integral is

and its value is given exactly by taking

. So the answer is D (and the value of the integral is exactly 39).