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0 votes
1 answer
231 views

Divide angles by coefficients relate to Fibonacci sequence

In the left Figure, consider a right triangle $OPA$ with $\angle {AOP} = 90^\circ$. Let $\ell$ be the reflection of $PO$ in $PA$ and $\ell$ meets $OA$ at $A_1$. Let $O_1$ be the center of the circle $(...
Đào Thanh Oai's user avatar
4 votes
0 answers
64 views

$(n-2)$-degree curve passing through $n(n-1)/2$ midpoints

It is known that in the plane, there is an unique conic passing through given $5$ points. For any $4$ points, there is 6 segments which vertex from these points. It is known that $6$ midpoints of ...
Vu Thanh Tung's user avatar
5 votes
0 answers
333 views

Which equation of a Butterfly?

Let $A, B$ be two points and $L$ be a line on the Euclidean Plane. Take two points $J, G$ on the line $L$ such that $JG=constant$. Let $AJ$ meet $BG$ at $P$, $AG$ meet $BJ$ at $Q$, then the locus of ...
Cố Gắng Lên's user avatar
4 votes
1 answer
226 views

A conjecture for a curve cuts a curve - variant Cayley-Bacharach's theorem

I propose a conjecture variant of Cayley-Bacharach's theorem. I'm an electrical engineer, I am not a mathematician. I don't know how to prove this result. Could you give a solution or let me know ...
Oai Thanh Đào's user avatar