Answer:
Dimensions to minimize surface are is 28 ft x 28 ft x 14 ft
Step-by-step explanation:
The Volume of a box with a square base of say;x cm by x cm and height
h cm is;
V = x²h
Now, the amount of material used is directly proportional to the surface area, hence we will minimize the amount of material by minimizing the surface area.
The formula for the surface area of the box described is given by;
A = x² + 4xh
However, we need A as a function of
only x, so we'll use the formula;
V = x²h
V = x²h = 10,976 ft³
So,
h = 10976/x²
So,
A = x² + 4x(10976/x²)
A = x² + 43904/x
So, to minimize the area, it will be at dA/dx = 0.
So,
dA/dx = 2x - 43904/x² = 0
Factorizing out, we have;
2x³ = 43904
x³ = 43904/2
x³ = 21952
x = ∛21952
x = 28 ft
since, h = 10976/x²
h = 10976/28² = 14 ft
Thus,dimension to minimize surface are is 28 ft x 28 ft x 14 ft
Answer: The exact length of segment HC is sqrt(3) units
The approximate length is roughly 1.73205080756888 (round that however you need to)
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Work Shown:
Let x = length of HC
Since AH = 3*HC, this means AH = 3*x
Draw out the picture. This step is optional but helpful in my opinion. The drawing is attached below.
After adding in the altitude BH, we have three similar triangles. So we can form the proportion shown below to solve for x
HC/BH = BH/AH
HC/3 = 3/AH ... replace BH with 3
x/3 = 3/AH ... replace HC with x
x/3 = 3/(3x) ... replace AH with 3x
x/3 = 1/x ... reduce
x*x = 3*1 ... cross multiply
x^2 = 3
x = sqrt(3) ... which is shorthand for "square root"
HC = sqrt(3)
HC = 1.73205080756888 which is approximate
(-3,0) Represents this function. Or are there answer choices?