Answer:
V = 34,13*π cubic units
Step-by-step explanation: See Annex
We find the common points of the two curves, solving the system of equations:
y² = 2*x x = 2*y ⇒ y = x/2
(x/2)² = 2*x
x²/4 = 2*x
x = 2*4 x = 8 and y = 8/2 y = 4
Then point P ( 8 ; 4 )
The other point Q is Q ( 0; 0)
From these two points, we get the integration limits for dy ( 0 , 4 )are the integration limits.
Now with the help of geogebra we have: In the annex segment ABCD is dy then
V = π *∫₀⁴ (R² - r² ) *dy = π *∫₀⁴ (2*y)² - (y²/2)² dy = π * ∫₀⁴ [(4y²) - y⁴/4 ] dy
V = π * [(4/3)y³ - (1/20)y⁵] |₀⁴
V = π * [ (4/3)*4³ - 0 - 1/20)*1024 + 0 )
V = π * [256/3 - 51,20]
V = 34,13*π cubic units
Answer:
6 7/8 inches
Step-by-step explanation:
The first thing to do is to get the measurements in either inches or feet. You can't have both. Let's go from feet to inches.
3 feet = 36 inches
13.75 feet = 165 inches
Now we can set up a proportion to solve for the number of inches the model is:
Now we can cross multiply:
36x = 247.5 so
x = 6.875 or 6 7/8 inches
Answer:
y = 1/8(x -2)^2 -1
Step-by-step explanation:
The vertex form of the equation of a parabola can be written as ...
y = (1/(4p))(x -h)^2 +k
for vertex (h, k) and vertex-to-directrix distance p. Here, the vertex has a y-value of -1, and the directrix has a y-value of -3, so the distance between them is -1 -(-3) = 2, and the desired equation with vertex (2, -1) is ...
y = 1/8(x -2)^2 -1
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<em>Comment on the graph</em>
One description of a parabola is that it is the locus of points equidistant from the focus and the directrix. I like to show that a point on the parabola (not the vertex) meets that requirement. That is what the dashed orange lines are for in the diagram. You can easily see that each has length 4.
