Why doesn't this integral yield the area of the sphere?
7241
Areas versus volumes of revolution: why does the area require approximation by a cone?
69764
Potential inside a polarized sphere
96414
Using residues to evaluate the integral $\int_{-\pi}^{\pi} \frac{\cos(n\theta)}{1-2a\cos(\theta)+a^2}d\theta$, $|a|<1$
69203
Calculus proof for the area of a circle
141434
Why is the field inside a hollow sphere zero?
22808
what are the possible values for integral
63726
Surface area of sphere $x^2 + y^2 + z^2 = a^2$ cut by cylinder $x^2 + y^2 = ay$, $a>0$
87391
Integral version of Ampere's law: why current outside the surface does not contribute to $\oint B\cdot d\ell$?
57953
Why does the volume of the unit sphere go to zero?
85764
Why is surface area not simply $2 \pi \int_{a}^{b} (y) dx$ instead of $2 \pi \int_a^b (y \cdot \sqrt{1 + y'^2}) dx$?
25509
evaluation of an integral involving algebraic numbers
18931
Is there really no way to integrate $e^{-x^2}$?
8502
Why aren't integration and differentiation inverses of each other?
5086
Why is the derivative of a circle's area its perimeter (and similarly for spheres)?
83621
Evaluating Contour Integral
26259
Get surface area of a mesh?
18458
How to plot the result of this singular integral?