user avatar
user avatar
user avatar
Fareed Abi Farraj
  • Member for 3 years, 10 months
  • Last seen more than a month ago
  • Aley, Lebanon
16 votes

Why can I solve an impossible equation using linear algebra?

9 votes

Are there any other methods to apply to solving simultaneous equations?

7 votes

Given $\mathbb E(5X+2)=12$ and $\mathbb E(X|Y)=Y^3$ compute $\mathbb E(Y^3)$

6 votes

Intuition behind determinant of a matrix with $2$ equal rows

5 votes
Accepted

There are 4 identical oak trees, 2 identical maple trees and 3 identical pine trees. How many arrangements start with maples?

4 votes
Accepted

Is it correct to assume that if $n \in \mathbf{Z}_+$ then $ \Big|\frac{\sin(n)}{2^n}\Big| \leq \Big|\frac{1}{2^n}\Big|$?

4 votes
Accepted

Suppose $BA$ is nilpotent, is it always true that $AB$ is nilpotent?

4 votes
Accepted

Mathematical average formula

4 votes

Area of quadrilateral using determinant/cross product

4 votes

How many 6-digit numbers are divisible by 7?

4 votes
Accepted

How to integrate $\ln(2+\sin x)$

3 votes

In modern algebra, what does $(m,n)=1$ mean?

3 votes

How to solve this equation without using "observation"

3 votes

Complex numbers $z=-3-4i$ polar form

3 votes
Accepted

Find measure of angle $x$

3 votes
Accepted

Is there a way to find $\cos(a+b)$ and $\cos(a-b)$ in terms of $\tan a$ and $\tan b$?

3 votes
Accepted

There are 3 red balls and 2 white balls in a box.

3 votes
Accepted

Showing expression of $dA$ in cartesian coordinates = $dA$ in cylindrical polar

3 votes

How to find an inverse of this type of functions?

2 votes

Why does a polynomial with real, simple roots change its sign between its roots?

2 votes

Prove that a tree with a vertex $v$ of degree $k > 1$ has at least $k$ leaves

2 votes

Number of ways to insert parentheses between elements

2 votes
Accepted

Understanding the limit $n \to \infty$ of the sequence $a_n := \frac{n!}{3^n}, n \in \mathbb{N}$

2 votes
Accepted

Let A, B, C be sets.

2 votes
Accepted

How do I solve $3xy=4xz=5yz$ ${x+y \over x-z}=?$

2 votes
Accepted

In how many ways can 4 cards be drawn randomly from a pack of 52 cards such that there are at least 2 kings and at least 1 queen among them?

2 votes

Textbook question about inner product and work.

2 votes

If $C(16,r) = C(16,r+2)$, then find $r$. Explain how you know.

2 votes

How many 4 digit numbers can be formed by digits 3, 1, 3, 1?

2 votes
Accepted

Using derivatives to compute velocity if only displacement is given

1
2 3 4 5
7