Skip to main content
Certainly not a dog's user avatar
Certainly not a dog's user avatar
Certainly not a dog's user avatar
Certainly not a dog
  • Member for 4 years, 10 months
  • Last seen more than a month ago
8 votes
Accepted

$n$ choose $k$ where $n$ is negative

6 votes

Prove the inequality is true

4 votes
Accepted

Chess Board (5×5) problem

4 votes

I don't understand the explanation of Proof by Contradiction

4 votes

Integrals from Brasilian Math Olympiad 2019

4 votes

Problem : What are our ages now?

3 votes
Accepted

Intersection of curve $ y = x^4 – 6x^3 + 12x^2 + cx + 1$

3 votes

Show that $\frac{3\> + \>\cos x}{\sin x}$ cannot have any value between $-2\sqrt2$ and $2\sqrt2$

3 votes

Peter purchased a pentagonal pen for his puppy Piper. Find the number of ways he can paint it such that no two sides are the same color.

2 votes
Accepted

Sigma Notation, to another Form of Sigma Notation and then a final result?!

2 votes

Limit of Product of Monomials, Specifically $\prod_{i=1}^{n}(x+i)$

2 votes
Accepted

Factoring $2^{2x} +2^{-2x}-2$

2 votes

$E=\{(x,x^2-3x+2)\in \mathbb R^2 : x\in \mathbb R\}$, $F=\{(a,a+2)\in \mathbb R^2 : a\in R\}$. What is $E\cap F$

2 votes

Combinatorics question about six letter sequences with repetition

2 votes

How to solve this ODE using integrating factors and differential form

2 votes

How to calculate $P(|X|>1.6)$

2 votes

Equation of circle touching three circles, two of which are intersecting

2 votes

How to prove that $\sqrt{2+\sqrt3}-\sqrt{2-\sqrt3}=\sqrt2$ without squaring both sides

2 votes

How do I use the limit definition to find the derivative on $a^x$?

2 votes
Accepted

Averages using integrals

2 votes

Angle between a vector and cross product of two vectors

2 votes

Solve 2nd order Ordinary differential equation $y d^2y/dx^2 -2 (dy/dx)^2 = y^2$

1 vote

Evaluating $\lim_{x\to 0}\frac{x}{2^x-1}$ without using L'Hôspital's rule

1 vote

What is the fastest way to calculate $(x+1)^3-(x-1)^3$?

1 vote

The eigenvalues of this symmetric Matrix

1 vote

Can't get the right result for a derivative of a trigonometric function

1 vote

A comment on $\int_{0}^{\pi} \frac{d\theta}{2 - \cos \theta}$

1 vote

Limit of f(x,y) as (x,y) approaches the origin point

1 vote

( Homework Help ) on Differential Equation $y^4dx+2xy^3dy=\frac{ydx-xdy}{x^3y^3}$

1 vote

To prove for multichoose $\big(\!{{a+b}\choose k}\!\big)= \sum_{j=0}^k \big(\!{a\choose j}\!\big) \cdot \big(\!{b\choose {k-j}}\!\big)$