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visits member for 3 years, 11 months
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15h
comment Unit circle is divided into $n$ equal pieces, what is the least value of the perimeters of the $n$ parts?
Is your diagram really optimal? An optimal solution would have only straight lines separating the pieces, surely?
15h
comment Is not Wiktionary’s definition of “step function” incorrect?
Ha! You got me there.
16h
comment Third point of elliptic curve $E: y^2 = x^3 + Ax + B$ given points $P_1=(x_1,y_1), P_2=(x_2, y_2)$ on $E$ (Weierstrass equation).
No, in the case that $P_3$ equals $P_1$ or $P_2$, then $Q$ can't equal $P_3$. If $P_3 = P_1$ or $P_3 = P_2$, then the line $P_1P_2$ must be a tangent to the curve at $P_3$, so the $y$-coordinate of $P_3$ can't be zero. (I am assuming here that neither $P_1$ nor $P_2$ is the Point at Infinity, since they were both presented as $(x,y)$-coordinates.)
17h
comment Are there any well known mathematicians who published very little?
@bobbym: You should have read it more carefully! I never read that tale before, but it is about his term in Parliament, not his fellowship of the Royal Society. He was an active member of the RS, so I knew your version to be false.
1d
comment Third point of elliptic curve $E: y^2 = x^3 + Ax + B$ given points $P_1=(x_1,y_1), P_2=(x_2, y_2)$ on $E$ (Weierstrass equation).
I never said that $Q$ couldn't equal $P_3$! And indeed this will happen if $P_1 = -P_2$.
1d
answered Third point of elliptic curve $E: y^2 = x^3 + Ax + B$ given points $P_1=(x_1,y_1), P_2=(x_2, y_2)$ on $E$ (Weierstrass equation).
1d
comment Are there any well known mathematicians who published very little?
@bobbym: That legend about Newton is simply false.
1d
comment A student appeared at 3 examinations…
@PerManne: You seem to be deliberately steering the OP away from the standard way of solving such problems!
1d
comment Is not Wiktionary’s definition of “step function” incorrect?
You should go there and edit it. That's what Wikipedia is all about!
1d
comment ? Confocal ellipses and hyperbolas cover whole Euclidean plane
Now I don't understand it at all.
1d
comment ? Confocal ellipses and hyperbolas cover whole Euclidean plane
Do you want to cover the plane with a mixture of hyperbolas and ellipses? Or do you want to do it separately, first for hyperbolas and then for ellipses? It seems to me that in any case, you are going to have trouble covering the mid-point of the foci.
1d
comment Question on continuity with [x]
If that is what your book really says, then it's wrong.
1d
comment Find the pair of values $a[i]$, $a[j]$ such that $a[i]\,\&\,a[j]$ is maximum
Yes, this works nicely. But just to make it explicit: the description of the algorithm assumes that all the binary representations have length k (after padding on the left with zeroes if necessary).
2d
comment Three planar vectors $x,y,z$ such that $x$ is orthogonal to $y + z$ and $z$
Please, edit your question!
2d
comment Calculating probabilities in horse racing!
A masterly exposition!
2d
comment Calculating probabilities in horse racing!
You can't do it, I'm afraid. There is no such formula, even for three horses.
2d
comment Three planar vectors $x,y,z$ such that $x$ is orthogonal to $y + z$ and $z$
It's not true, in general. (In $\mathbb R^2$ it's true. If this is what you meant, please edit your question.)
2d
comment Can you factor before finding derivative?
3 is not a square. Not in the sense that you mean, anyway. (And you need to use parentheses here $-$ try editing your post.)
2d
comment How much distance did messenger cover?
Perhaps you could provide us with links to the "problems that were already on the forum"?
2d
comment Can you factor before finding derivative?
How do you propose to factor your function? Whether it is $$\frac{x^2-3}{x-3}$$ or $$x^2-\frac{3}{x}-3,$$ I don't see it.