Fareed Abi Farraj's user avatar
Fareed Abi Farraj's user avatar
Fareed Abi Farraj's user avatar
Fareed Abi Farraj
  • Member for 5 years, 7 months
  • Last seen more than a month ago
  • Aley, Lebanon
8 votes
3 answers
469 views

What is the radius of this circle?

5 votes
2 answers
2k views

The ant and the rubber string.

5 votes
0 answers
301 views

Schrödinger equation on a torus

4 votes
3 answers
203 views

Comparing numbers of the form $c+\sqrt{b}$ (eg, $3+3\sqrt{3}$ and $4+2\sqrt{5}$) without a calculator

3 votes
0 answers
131 views

Will a strong tournament still be a strong tounament after removing a vertex from it?

2 votes
2 answers
63 views

When is this statement true $\frac{a}{s} \in S^{-1}I \implies a \in I$?

2 votes
1 answer
70 views

Proof of a lemma about irreducible fractions

2 votes
1 answer
107 views

Is $\operatorname{rk}(\bar AA)=\operatorname{rk}(A^*A)$ ??

2 votes
1 answer
153 views

Regular Pentagon and Complex Numbers

2 votes
1 answer
178 views

How to get the jacobian of this change of variables?

2 votes
1 answer
1k views

Matrix theory- Contraction

2 votes
1 answer
44 views

How to locate $O$ if $OA=2OC$?

2 votes
1 answer
155 views

How to know if a Numerical method gives an exact solution?

1 vote
1 answer
68 views

How can this integral be solved? Is is an indefinite integral?

1 vote
1 answer
61 views

The proof of an inequality in Linear Algebra and its Applications

1 vote
2 answers
123 views

Strong tournaments

1 vote
2 answers
65 views

Why a function that is $0$ in a neighborhood of a point must have a $0$ derivative at that point?

1 vote
0 answers
74 views

Why is $v_2(3^t-1)\ge t$?

1 vote
2 answers
92 views

Easiest way to solve $\frac{2}{9}x=\sin(\frac{\pi}{9}x)$

1 vote
1 answer
64 views

Rank of a simple matrix

1 vote
2 answers
978 views

When is $rk(A+B)=rk(A)+rk(B)$?

0 votes
2 answers
66 views

Rings of fractions

0 votes
1 answer
56 views

Optimization over a binary (or discrete) variable

0 votes
0 answers
78 views

Red and black balls (Pretty easy I think)

0 votes
4 answers
288 views

LU factorization of a simple matrix

0 votes
1 answer
72 views

Find 2 equations from the given graph to get the 2 unknowns

0 votes
0 answers
21 views

Is the stability of an ordered digraph $D$ equal to the number of pairwisely disjoint directed paths covering $D$?

0 votes
1 answer
99 views

Proving that $e(X,Y)\ge k$

0 votes
1 answer
297 views

Example on a product topology

0 votes
1 answer
538 views

How to find $ \lim_{x\to 2} \frac{x-\sqrt{x+2}}{\sqrt{4x+1} -3} $ without derivatives and l'Hopital?