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.
I highly recommend you use photomath for this. but i have the answer!
26-16x is the answer
I got 36 remember first x / and then -+
<DSR + <SRD + <RDS = 180° (Angle sum property)
2x + x +3x = 180°
6x = 180°
x = 180°/6
x = 30°
So, <SRD = x = 30°
<RDS = 3x = 3(30°) =90°
<DSR = 2x = 2(30°) = 60°
Hope it helps !
✌️
Jai hind !
Answer:B
Step-by-step explanation: