Answer:
The rate of change in surface area when r = 20 cm is 20,106.19 cm²/min.
Step-by-step explanation:
The area of a sphere is given by the following formula:

In which A is the area, measured in cm², and r is the radius, measured in cm.
Assume that the radius r of a sphere is expanding at a rate of 40 cm/min.
This means that 
Determine the rate of change in surface area when r = 20 cm.
This is
when
. So

Applying implicit differentiation.
We have two variables, A and r, so:



The rate of change in surface area when r = 20 cm is 20,106.19 cm²/min.
Answer:
0.01 to 0.99, the multiplier in scientific notation always has to be a decimal less than 1 and greater than 0.
Step-by-step explanation:
Answer:
70%
Step-by-step explanation:
56 vanilla cupcakes
------------------------------- = 0.7, or 0.7(100%), or 70%
80 students
70% of students picked vanilla.
Answer:
BEC = 60 degrees can i have brainlest
Step-by-step explanation: cd is 30 so it cant be 90 degrees abe is 90 150 is aed so only answer left is 60
Answer:
<u>400 miles</u>
Step-by-step explanation:
2 hours = 100 miles
Therefore, he will drive 4 times the distance given 4 times the time taken.
=> 100 x 4
=> <u>400 miles</u>