I believe these deal with joint variation. Please help! I am lost.
Describe the combined variation that is modeled by each formula.
V = Bh÷3
V = <pi>(r^2)h
h = V÷<pi>(r^2)
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Write the funtion that models each variation. Find z when x = 4 and y = 9.
z varies directly with x and inversely with y. When x = 6 and y = 2, z = 15.
z varies jointly with x and y. When x = 2 and y = 3, z = 60
z varies directly with the square of x and inversely with y. When x = 2 and y = 4, z = 3.
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A concrete supplier sells premixed concrete in 300-ft^3 truckloads. The area (A) that the concrete will cover is inversely proportional to the depth (d) of the concrete.
a. Write a model for the relationship between the area and the depth of a truckload of poured concrete.
b. What area will the concrete cover if it is poured to a depth of .5 feet? A depth of 1 ft? A depth of 1.5 ft?
c. When the concrete is poured into a circular area, the depth of the concrete is inversely proportional to the square of the radius (r). Write a model for this relationship.[/b]
Describe the combined variation that is modeled by each formula.
V = Bh÷3
V = <pi>(r^2)h
h = V÷<pi>(r^2)
---------
Write the funtion that models each variation. Find z when x = 4 and y = 9.
z varies directly with x and inversely with y. When x = 6 and y = 2, z = 15.
z varies jointly with x and y. When x = 2 and y = 3, z = 60
z varies directly with the square of x and inversely with y. When x = 2 and y = 4, z = 3.
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A concrete supplier sells premixed concrete in 300-ft^3 truckloads. The area (A) that the concrete will cover is inversely proportional to the depth (d) of the concrete.
a. Write a model for the relationship between the area and the depth of a truckload of poured concrete.
b. What area will the concrete cover if it is poured to a depth of .5 feet? A depth of 1 ft? A depth of 1.5 ft?
c. When the concrete is poured into a circular area, the depth of the concrete is inversely proportional to the square of the radius (r). Write a model for this relationship.[/b]