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0 votes
0 answers
54 views

Generalization of why the area of a surface of revolution is not $2 \pi \int_{a}^{b} (y) dx$

Based on the posts Areas versus volumes of revolution: why does the area require approximation by a cone? and Why is surface area not simply..., approximating an ND quantity in an ND region using N-1D ...
Nafiul Khandaker's user avatar
0 votes
1 answer
45 views

What is the maximum value of $H(r)=\frac{1}{3} \pi r^2\sqrt{l-r^2} $ when $l=7$?

What is the maximum value of $H(r)=\frac{1}{3} \pi r^2\sqrt{l-r^2} $ when $l=7$? I've computed the minima using derivative method,but I'm not able to calculate the maxima under the given condition... ...
Anwar's user avatar
  • 119
0 votes
2 answers
81 views

Confusion About Bounds on a Volume of Revolution

I'm having a little bit of trouble understanding how to determine the bounds and manipulate the equations of a complex solid of rotation problem. Here's a prime example of where I struggle: Taken ...
N. Bar's user avatar
  • 1,610
4 votes
1 answer
47 views

Solid of Revolution About y=2

Find the volume of the solid of revolution bounded by $y=x^4$ and $y=1$ rotated about $y=2$. Here's my attempt: $\pi\displaystyle\int_{-1}^1(2-x^4)^2dx$ $\pi\displaystyle\int_{-1}^1(4-4x^4+x^8)dx$ ...
N. Bar's user avatar
  • 1,610