Volume of cylinder:
V = πr²h
The desired volume is 1 Liter = 1000 cm³
1000 = πr²h
h = 1000/πr²
Surface area of cylinder:
S.A = 2πr² + 2πr²h
We substitute the value of h from the first equation:
S.A = 2πr² + 2πr(1/πr²)
S.A = 2πr² + 2/r
Now, to minimize surface area, we differentiate the expression with respect to r and equate to 0.
0 = 4πr - 1000/r²
4πr³ - 1000 = 0
r = 4.3 cm
h = 17.2 cm
Answer:
-5.2
Step-by-step explanation:
-8+1.5 = -6.5
-6.5 * 4/5 = -6.5 * 0.8 = -5.2
Answer:
72
Step-by-step explanation:
2x2x13=52
2x2x5=20
52+20=72