Finding Volume of Solid with Rectangle Cross-Sections | Geometry Homework

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Homework Statement


Find the volume of the solid whose base is the region bounded by the lines x=0, y=0, and y= 3*(4-x)^1/2 and whose corss-sections perpendicular to the x-axis are rectangles whose heights are two times the base.


Homework Equations



b*h


The Attempt at a Solution



The function ends at 4, so limits are 0 to 4.
Height is 2x base
so we have 2b^2

4
∫2*(3(4-x)^1/2)^2
0

And then solve the definite integral, I believe that is correct.
 
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Chas3down said:

Homework Statement


Find the volume of the solid whose base is the region bounded by the lines x=0, y=0, and y= 3*(4-x)^1/2 and whose corss-sections perpendicular to the x-axis are rectangles whose heights are two times the base.


Homework Equations



b*h


The Attempt at a Solution



The function ends at 4, so limits are 0 to 4.
Height is 2x base
so we have 2b^2

4
∫2*(3(4-x)^1/2)^2
0

And then solve the definite integral, I believe that is correct.

Looks correct to me as well.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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