Christian Blatter

ETH Zurich (Switzerland)

math.ethz.ch/~blatter

Age: 79

11h
answered Computation of determinant for Using Inverse Function Theorem
15h
comment Mid '|' in math?
It's one of the most unfortunate notations in all of mathematics: A completely symmetric symbol denoting a highly asymmetric relation.
16h
answered Why is $[\partial f/\partial x,2\partial f/\partial y,\partial f/\partial x]$ NOT a vector?
1d
answered Trouble understanding Linear transformation question
1d
answered How do I compute the density of R?
1d
awarded Nice Answer
1d
answered Volume with a Cubic
1d
revised Finding vertical spacing between string wound on the cylinder.
added 129 characters in body
1d
answered Finding vertical spacing between string wound on the cylinder.
1d
answered How to calculate the area covered by any spherical rectangle?
1d
revised Calculation of limit without stirling approximation
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1d
revised Replacing entries of dice by average of it neighbours
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2d
answered Differential of $Re(e^{x-iy})$
2d
comment Show that a space curve lies entirely on a plane.
This curve does not lie on a plane.
2d
revised Replacing entries of dice by average of it neighbours
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2d
answered Replacing entries of dice by average of it neighbours
2d
comment Converting a rotated ellipse in parametric form to cartesian form
@Narasimhan: The given paramatrization can only produce ellipses (maybe degenerated to a segment or a point). Everything in sight here is considered real.
2d
comment Converting a rotated ellipse in parametric form to cartesian form
This choice of $R(t)$ is geometrically natural under the circumstances. Maximizing, e.g., $y(t)$ gives you the points where the tangent is parallel to the $z$-axis, and not points on the main axes of the ellipse. When the ellipse is not centered at the origin you have to subtract off the center from the parametric representation before starting with the above calculations.
2d
revised Converting a rotated ellipse in parametric form to cartesian form
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2d
answered Converting a rotated ellipse in parametric form to cartesian form
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