Answer:
The answer would be C
Step-by-step explanation:
The area of a circle:
A = πr²
dA/dr = 2πr
We are given dA/dt, using the chain rule
dr/dt = dA/dt x dr/dA
dr/dt = 1 x 1/2πr
When circumference = 2 cm:
2 = 2πr
r = 1/π; putting this value of r
dr/dt = 1/2π(1/π)
dr/dt = 1/2 cm/s
The radius is increasing at a rate of 1/2 cm/s.
36
25:9
25*4 = 100
9*4 = 36
6/2
