Answer:
dV/dt = 155.74 ft^3/minute
Step-by-step explanation:
Volume V = Area × thickness
Area A= πr ^2
Thickness = 0.2 ft
Volume V = 0.2A = 0.2πr^2
V = 0.2πr^2
Differentiating both sides;
dV/dt = 0.2π × 2r dr/dt = 0.4πr.dr/dt
Given;
r = 400 ft
dr/dt = 0.31 ft/minute
π = 3.14
Substituting the values
dV/dt = 0.4πr.dr/dt = 0.4 × 3.14 × 400 × 0.31
dV/dt = 155.74 ft^3/minute
the answer for this question is 64-144a+108a^2-27a^3
Is that a question???????
The answer that I got is C=-6