<span>You are under contract to design a storage building with a square base and a volume of 12000 cubic feet. the cost of materials is $4 per square foot for the floor, $18 per square foot for the walls and $6 per square foot for the roof. find the width of the square base that minimizes the cost of materials. XD
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Answer:
The yellow one
Step-by-step explanation:
Use the sum of angles's trigonometric identity formula:
cos(A+B)=(cosAcosB-sinAsinB)
x+y=4cos(t+π/6)+2sint=4(cost*cosπ/6-sint*sinπ/6)+2sint
recall that cosπ//6=√3/2, and sinπ/6=1/2:
4(cost*cosπ/6-sint*sinπ/6)+2sint=4[(√3/2)cost-(1/2)sint]+2sint
simplify:2√3cost-2sint+2sint=2√3cost
Let x be he length of middle piece.
3x = length of longer piece.
x-5 = length of shortest piece.
x + 3x + x-5 = 40
5x - 5 = 40
5x = 45
x = 45/5
x = 9. ( Size of middle piece )
Given that the longer piece is 3 times the size of middle piece,
Longest piece = 3 x 9 = 27.
Size of longest piece = 27 feet
Size of middle piece = 9 feet
Size of smaller piece = 40 - (27+9)
= 40 - 36
= 4 feet.
Thank you.
Answer: You take the 2 middle columns in this case the purple gray looking one and the brown one and add them together divide them by 2
Step-by-step explanation:
