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ulead86
  • Member for 11 years
  • Last seen more than 4 years ago
45 votes

Are contractible open sets in $\mathbb{R}^n$ homeomorphic to $\mathbb R^n$?

16 votes

Proving $\sum\limits_{k=1}^{n}{\frac{1}{\sqrt{k}}\ge\sqrt{n}}$ with induction

7 votes
Accepted

Is the function $\frac{x^2-x-2}{x-2}$ continuous?

6 votes
Accepted

Trisecting a paper using hand and without using a ruler or compass

5 votes

Direct proof: $\sqrt{13}$ is irrational

4 votes

Why does $16^0 = 1$ and not $0$

4 votes

What is the connection between Chinese remainder theorem and Lagrange interpolation?

3 votes
Accepted

How to use Fermat's theorem in congruence problems

3 votes

How many real roots are there to $2^x=x^2$?

2 votes

How to make a parabola in GeoGebra?

2 votes

How to convert octal to decimal?

2 votes

How to solve $\lim_{x\to 0}\frac{\sqrt{x^2+4x+5}-\sqrt{5}}{x}$?

2 votes

Proving two integral inequalities

2 votes

Evaluate the following integral, $\int\sqrt{4-\sqrt{x}}dx$

2 votes
Accepted

Let $G$ be a connected solvable algebraic group. If $T$ is a maximal torus of $G$, then $C_G(T)$ is nilpotent

2 votes

Solutions to Linear Diophantine equation $15x+21y=261$

2 votes
Accepted

Is this definition of a quantile proper?

1 vote

Proofs from the BOOK: Bertrand's postulate Part 3: $\frac{2}{3}n<p \leq n \rightarrow$ no p divides $\binom{2n}{n}$

1 vote
Accepted

$u$-substitution into integral

1 vote

Is $ \forall\space x \in \mathbb{R} \space \exists \space y \in \mathbb{R} \space(x+y^2=10)$ true or false?

1 vote
Accepted

How to prove that the exterior angle sum of an n-sided polygon is 360 degrees?

1 vote

probability and combinations

1 vote

Triangle $\Delta ABC$: Proof $\angle ADB<\angle ACB$

1 vote

How to find the intersection of three spheres (full solutions)?

1 vote

Finding the Unknown Coordinate when given Distances from two points

1 vote
Accepted

Number theory: 2 numbers within a set with same difference

1 vote

How to integrate $\frac{1}{x^4\sqrt{(x^2+3)}}$

1 vote
Accepted

Prove that $PT$ bisects $\angle{ATB}$ with two touching circles.

1 vote

Integrating secant squared times tangent

1 vote

In the equation $y = ax^2 + bx + c$ of a parabola, what do "$a$", "$b$", "$c$" represent?