The answer is 8.333333 it goes on and 3 is repeating.
11: 4,874 > 4,784 > 4,687
12: 8.09 > 8.057 > 8.023
13: 15.820 > 15.280 > 15.000
14: 43,628 > 40,628 > 34,628
15: 395.050 > 395.009 > 395.005
Answer:
DA/dt = 75.27 cm²
Step-by-step explanation:
Cube Volume = V(c) = 683 cm³
DV(c) /dt = 824 cm³
V(c,x) = x³
Then
DV(c,x)/ dt = 3x² Dx/dt
( DV(c,x)/ dt )/ 3x² = Dx/dt (1)
Now as V(c,x) = x³ when V(c,x) = 683 cm³ x = ∛683
x = 8.806 ( from excel)
And by subtitution of this value in equation (1)
Dx/dt = ( DV(c,x)/ dt )/ 3x² ⇒ Dx/dt = 824 / 3*x²
Dx/dt = 824 /3*77.55
Dx/dt = 824/232,64
Dx/dt = 3,542
Then we got Dx/dt where x is cube edge. The area of the face is x² then
the rate of change of the suface area is
DA/dt = ( Dx/dt )²*6 ( 6 faces of a cube)
DA/dt = (3.542)²*6
DA/dt = 75.27 cm²
