Volume of region roated about specified axi

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In summary, the volume of a region rotated about a specified axis is the amount of space that the region occupies when it is rotated around a specific line or axis. To calculate this volume, you can use the formula V = ∫<sub>a</sub><sup>b</sup>π(r(x))^2dx, taking into account the limits of integration, the distance from the axis of rotation to the edge of the region, and the infinitesimal width of the region. This differs from the volume of a region in its original position, as it also considers the added space from the rotation. Real-life applications of this concept can be found in various fields, such as engineering, architecture, and physics. An example of calculating the volume of
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Painguy
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Homework Statement



y = e^(-x), y = 0, x = -1, x = 0, about x = 1

Homework Equations





The Attempt at a Solution


2pi∫ (1-x)(e^(-x) dx from -1 to 0

=2pi∫ e^(-x) -x*e^(-x) dx from -1 to 0
=2pi(-e^(-x) - ∫x*e^(-x) dx from -1 to 0
u=x
du=dx
dv=e^(-x)dx
v=-e^(-x)
2pi(-e^(-x)-(-xe^(-x) +∫e^(-x)dx))
2pi(-e^(-x) +xe^(-x) +e^(-x))
2pi(xe^(-x)) from -1 to 0
2pi(e)

is this right?
 
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Seems ok to me.
 

1. What is the volume of a region rotated about a specified axis?

The volume of a region rotated about a specified axis is the amount of space that the region occupies when it is rotated around a specific line or axis. It is typically measured in cubic units, such as cubic inches or cubic meters.

2. How do you calculate the volume of a region rotated about a specified axis?

To calculate the volume of a region rotated about a specified axis, you can use the formula V = ∫abπ(r(x))^2dx, where a and b represent the limits of integration, r(x) is the distance from the axis of rotation to the edge of the region at a given value of x, and dx represents an infinitesimal width of the region.

3. What is the difference between the volume of a region and the volume of a region rotated about a specified axis?

The volume of a region is the amount of space that the region occupies in its original position, while the volume of a region rotated about a specified axis takes into account the extra space created by the rotation. In other words, the latter accounts for the space that is added when the region is rotated around the specified axis.

4. Can you provide an example of calculating the volume of a region rotated about a specified axis?

Sure, let's say we have a region bounded by the curve y = x2, the x-axis, and the lines x = 0 and x = 1. If we rotate this region about the x-axis, we can use the formula V = ∫01π(x^2)^2dx = π/5 cubic units. This represents the volume of the solid created by rotating the region about the x-axis.

5. What are some real-life applications of calculating the volume of a region rotated about a specified axis?

Calculating the volume of a region rotated about a specified axis has many real-life applications, such as in engineering, architecture, and physics. For example, it can be used to determine the volume of a water tank, the capacity of a fuel tank, or the amount of material needed to create a specific shape or structure. It can also be used to calculate the moment of inertia, a crucial parameter in understanding the rotational motion of objects.

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