Christian Blatter

ETH Zurich (Switzerland)

math.ethz.ch/~blatter

Age: 78

1h
revised Hint finding exact value of half-angle when $\tan (\theta) = {3}$
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3h
answered Is there a way to derive the chain rule using the definition of the differential of a function?
3h
revised Tangent at a singular point
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5h
answered Proving a space is a manifold
5h
revised Tangent at a singular point
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7h
revised Weierstrass Caratheodory on open interval
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1d
answered How exactly does the response "infintely many" answer the question of "how many"?
1d
answered Problem using Stokes's Theorem - Boundary Curve, Unit Normal Vector [Stewart P1097 16.8.5]
1d
answered Weierstrass Caratheodory on open interval
1d
comment Understanding Indexed Families
The idea that a family is a set of subsets of some set is definitely wrong.
1d
answered What is a fast method for evaluate this trigonometric series?
1d
comment How many equilateral triangles can be inscribed in a triangle?
When "inscribed" means that all vertices of the inscribed triangle have to lie on the circumference of the given triangle, the answer is $\infty$: The given triangle has at least one angle $\leq60^\circ$, and it is then easy to inscribe small equilateral triangles with two vertices on one adjacent side and the third vertex on the other adjacent side.
2d
comment Real analysis question involving inhomogenous linear ODE
I chose $x_0$ to make my $c(x_0)=0$, so that fulfilling the initial condition $f(x_0)=y_0$ would be simpler.
2d
answered Tangent at a singular point
2d
answered Real analysis question involving inhomogenous linear ODE
Apr
16
answered How to compute Lipschitz Constant for multivariate function $f(x,y)=1-xy$?
Apr
16
revised How minimize $\sum p_b \ln{p_b}$?
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Apr
15
comment Equal perimeter and area
@Gerry Myerson: See my edit.
Apr
15
revised Equal perimeter and area
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Apr
13
comment How minimize $\sum p_b \ln{p_b}$?
The quantities $m$ and $n$ are the only parameters of this problem. It may be that in the end you obtain a bound which is independent of $m$.
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