Hello!

Recall that:
can be rewritten as:

Use the equation for the derivative of a log expression:

Substitute in the values in the expression:

Answer:
132 ft
Step-by-step explanation:
The radius is 21 ft
We want to find the circumference
C = 2 * pi *r
Letting pi = 22/7
C = 2 * 22/7 * 21
C = 132 ft
Answer:
425261625
Step-by-step explanation:
1+2-4252+425251-34%+5%
Answer #1- 8 mins
Answer #2-$0.571
Explanation for #1:
For this first equation you need to find 1 mike per ___ minutes. To get from 10 to 1, you need to divide by 10. This can also be put into this equation—
10x=80
So, to find how many minutes for each mile, divide 80 by 10. This will result in 8. This means that Dan ran 1 mile in 8 minutes.
Explanation for #2:
For this next one we see that we need to find how much Yoko spent on each pound of rice.
Since we are trying to find 1 pound of rice per ___ dollars, we need to divide both 14 and 8 by 14. This can also be put into this equation—
14x=8
Once this is done we know that 1 pound of rice is equal to 0.571428571428571 cents. But, since you are required to round to the nearest hundredth, the answer will only be $0.571.
Hope this helps comment below for more questions :)