Answer: 12
Step-by-step explanation:
Answer:
10 ft x 10 ft
Area = 100 ft^2
Step-by-step explanation:
Let 'S' be the length of the southern boundary fence and 'W' the length of the eastern and western sides of the fence.
The total area is given by:
![A=S*W](https://tex.z-dn.net/?f=A%3DS%2AW)
The cost function is given by:
![\$ 120 = \$3*2W+\$6*S\\20 = W+S\\W = 20-S](https://tex.z-dn.net/?f=%5C%24%20120%20%3D%20%5C%243%2A2W%2B%5C%246%2AS%5C%5C20%20%3D%20W%2BS%5C%5CW%20%3D%2020-S)
Replacing that relationship into the Area function and finding its derivate, we can find the value of 'S' for which the area is maximized when the derivate equals zero:
![A=S*(20-S)\\A=20S-S^2\\\frac{dA}{dS} = \frac{d(20S-S^2)}{dS}\\0= 20-2S\\S=10](https://tex.z-dn.net/?f=A%3DS%2A%2820-S%29%5C%5CA%3D20S-S%5E2%5C%5C%5Cfrac%7BdA%7D%7BdS%7D%20%3D%20%5Cfrac%7Bd%2820S-S%5E2%29%7D%7BdS%7D%5C%5C0%3D%2020-2S%5C%5CS%3D10)
If S=10 then W =20 -10 = 10
Therefore, the largest area enclosed by the fence is:
![A=S*W\\A=10*10 = 100\ ft^2](https://tex.z-dn.net/?f=A%3DS%2AW%5C%5CA%3D10%2A10%20%3D%20100%5C%20ft%5E2)
1.25 If you multiple 12 × 1.25=15
Area=height times base (for some prisms including cylinders)
vcylinder=hpir²
h=height
therefor pir²=base area
vcylinder=height times aeraofbase
given
h=9
v=324pi
324pi=9(basearea)
divide both sides by 9
36pi=areabase
the area of the base is 36pi square cm (put 36 in the blank since the pi is already there)
The answer should be D.
The square root of two.