Answer:
the dimensions that minimize the cost of the cylinder are R= 3.85 cm and L=12.88 cm
Step-by-step explanation:
since the volume of a cylinder is
V= π*R²*L → L =V/ (π*R²)
the cost function is
Cost = cost of side material * side area + cost of top and bottom material * top and bottom area
C = a* 2*π*R*L + b* 2*π*R²
replacing the value of L
C = a* 2*π*R* V/ (π*R²) + b* 2*π*R² = a* 2*V/R + b* 2*π*R²
then the optimal radius for minimum cost can be found when the derivative of the cost with respect to the radius equals 0 , then
dC/dR = -2*a*V/R² + 4*π*b*R = 0
4*π*b*R = 2*a*V/R²
R³ = a*V/(2*π*b)
R= ∛( a*V/(2*π*b))
replacing values
R= ∛( a*V/(2*π*b)) = ∛(0.03$/cm² * 600 cm³ /(2*π* 0.05$/cm²) )= 3.85 cm
then
L =V/ (π*R²) = 600 cm³/(π*(3.85 cm)²) = 12.88 cm
therefore the dimensions that minimize the cost of the cylinder are R= 3.85 cm and L=12.88 cm
Answer:
Third answer (she is incorrect because she should have squared each leg length and then found the sum.)
Step-by-step explanation:
The pythagorean theorem states that a²+b²=c². This is not equivalent to (a+b)²=c² (due to FOIL expansion, this expands to a²+2ab+b²=c²).
This matches with the third answer, as she has to do a² and b≥ separately.
**This question involves expanding perfect squares, which you may wish to revise. I'm always happy to help!
Answer:
66 cups
Step-by-step explanation:
16 cups in 1 gallon
16*6 = 96 cups in 6 gallons
96 - 30 = 66
A 100 m
B 900m
C -5,100m
D- 8,800
Answer:
22
Step-by-step explanation:
(3² - 5 + 7) × (2² - 2)
(9 - 5 + 7) × (4 - 2)
(4 + 7) × (2)
11 × 2
22
