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Find the area of the surface of the half cylinder {(r,0,z): r = 3, 0 ≤ 0 ≤ π, 0 ≤ z ≤ 8} using a parametric description of the surface.

Set up the integral for the surface area using the parameterization u = 0 and v = z.
... ...
∫ ∫ (__) du dv
0 0
(Type an exact answers, using as needed.)

The surface area is ....
(Type an exact answer, using tas needed.)

1 Answer

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Final answer:

The surface area of the half-cylinder with radius 3 and height 8 can be found by multiplying the circumference of the half circle, πr, by the height, giving us an area of 24π. This is represented by the double integral ∫_0^π ∫_0^8 3 dz dθ.

Step-by-step explanation:

The student asked to find the area of the surface of the half cylinder with the given parametric description. Since we have a half cylinder, we can find its surface area by calculating the area of the curved surface without the circular ends.

The curved surface of a half cylinder can be thought of as a rectangle unrolled, with width equal to the height of the cylinder and length equal to the circumference of the half circle (which is πr for a half circle).

The surface area A of a half-cylinder can be found using the formula:

A = (Circumference of half circle) × (Height of cylinder)

A = (π × r) × h

Where r is the radius and h is the height. Inserting the given values, r = 3 and h = 8, we have:

A = (π × 3) × 8

A = 24π

Therefore, the integral for the surface area using the parameterization u = θ and v = z is:

∫∫ πθ dz dθ

The limits for u are from 0 to π, and for v from 0 to 8, so the double integral is:

∫_0^π ∫_0^8 3 dz dθ

Which simplifies to:

A = 24π

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