Skip to main content
open problem's user avatar
open problem's user avatar
open problem's user avatar
open problem
  • Member for 3 years, 5 months
  • Last seen more than 2 years ago
5 votes
Accepted

Why are $\text{versin}(x)=1-\cos(x)$, $\text{coversin}(x)=1-\sin(x)$, $\text{vercosin}(x)=1+\cos(x)$ no longer used in maths?

5 votes
Accepted

Eliminate $\theta$ from the equation $\sec \theta + \tan \theta = a+\sqrt b,$

5 votes

Does the order of the Fibonacci sequence's initial values matter?

4 votes
Accepted

If $p$ is an odd prime (different than $5$) prove that $10 \mid p^{2}-1$ or $10 \mid p^{2}+1$

4 votes
Accepted

What is the FTC of a function from the perspective of Stokes' theorem?

4 votes
Accepted

How to find all polynomials that follows the equation $P(P'(x)) = P'(P(x))$

3 votes

Question about angles in a triangle having a median line

3 votes

If ABC is a right triangle with right angle at C, and if BD is any line cutting AC at point D, prove that $BD^2+AC^2=AB^2+DC^2$

3 votes
Accepted

Does the linear recurrence theory hold for inequalities?

3 votes

Given n mod 2 = 1 and n mod 3 =1. Find n mod 5. How to solve algebraically knowing n = 7

3 votes
Accepted

Reference on Fixed Point Theory

2 votes

why is $\sqrt{x^2} \ne x$?

2 votes

$\{r_n: n = 1,2,...\}$ enumeration of the rational numbers in $[0, 1]$. Show $\sum_{n = 1}^\infty \frac{1}{2^n}f(|x - r_n|)$

2 votes
Accepted

Find sequence of functions such that $||f_n||_1\to0 , ||f_n||_{\infty}\to \infty$

2 votes
Accepted

Formula for finding $\cos(\theta)$?

2 votes
Accepted

Validity of Limits? Proof that $\lim_{x \to 1} \frac{x^{\alpha}-1}{x-1} = \alpha$ when $\alpha \in \mathbb{R}$

2 votes
Accepted

prove following combinatorial identity

1 vote
Accepted

How to express series summation notation in reverse?

1 vote

Show that $\alpha$ is a homomorphism. Also, find $\text{ker}(\alpha)$, and decide if $\alpha$ is onto.

1 vote
Accepted

Group of symmetries of a parallelepiped in three dimension.

1 vote

Convergence of sequence and serie

1 vote

For $x_{n+1}=x_n-x_n^3$, with $|x_1|>1$. What about the convergence?

1 vote
Accepted

Can we treat $\operatorname{span}()$ as an operator by taking the span of both sides of a relation?

1 vote

How to Show that an $n$-finned Hyperplane is not Homeomorphic to $\mathbb{R}^m$

1 vote

Show that the solution of this (nonlinear) ODE cannot remain bounded as $t\to\infty$

1 vote
Accepted

How can I tell if a set is compact and connected?

1 vote

Doubt on proof of theorem 14.22 of Rudin's Real and Complex Analysis

1 vote

Why can you transition from a Riemann Sum to an Intergal?

1 vote

Quadratic Form of $A^2, A^3$

1 vote
Accepted

What can be said about a linear transformation if there is a basis where its matrix is symmetric?