Answer:
The rate at which the radius is increasing
dr/dt = 1.91 cm/s
Step-by-step explanation:
The circumference C of a circle can be written as;
C = 2πr .....1
Where;
r = radius
The rate at which the circumference of the circle
is increasing can be written as dC/dt;
Differentiating equation 1, we have;
dC/dt = 2π dr/dt
Making dr/dt the subject of formula;
dr/dt = (dC/dt)/2π
Given;
dC/dt = 12cm/s
Substituting the value of dC/dt;
dr/dt = 12/2π
dr/dt = 1.909859317102 = 1.91 cm/s
The rate at which the radius is increasing dr/dt is 1.91 cm/s
