This account is temporarily suspended network-wide. The suspension period ends on Aug 20, 2028 at 21:36.
user85798's user avatar
user85798's user avatar
user85798's user avatar
user85798
  • Member for 10 years, 7 months
  • Last seen this week
87 votes
Accepted

Why is $(2+\sqrt{3})^{50}$ so close to an integer?

81 votes

Rules for Product and Summation Notation

30 votes
Accepted

When written in decimal notation, every square number has at most 1000 digits that are not 0 or 1. True or false?

20 votes

Find the Area of the ellipse

16 votes

Why $\sum_{k=1}^{\infty} \frac{k}{2^k} = 2$?

16 votes

Why can't you square both sides of an equation?

12 votes

I need help finding integral of $\frac{1}{x^2+x^4}$

12 votes

Interesting but short math papers?

11 votes

Which is greater, $e^{\pi}$ or $\pi^e$?

10 votes

How to determine countability of $\Bbb N \times \Bbb N \times \Bbb N$?

9 votes

Show that $\sum_{n=0}^\infty r^n e^{i n \theta} = \frac{1- r\cos(\theta)+i r \sin(\theta)}{1+r^2-2r\cos(\theta)}$

8 votes
Accepted

Evaluate $\int_0^e{W(x)}\,\mathrm{d}x$

7 votes
Accepted

Cantor's Theorem for $\Bbb N$.

7 votes

Infinite Product $\prod\limits_{k=1}^\infty\left({1-\frac{x^2}{k^2\pi^2}}\right)$

6 votes

Double Angle Formula?

6 votes
Accepted

Proof by induction that fibonacci sequence are coprime

6 votes

Proof of divergence of $1/2 + 1/3 + 1/5 + 1/7 + 1/11 +....$

5 votes
Accepted

Integrate $\int \frac{\sin^2(x)}{1+\sin^2(x)}dx$

5 votes
Accepted

Prove that $4x(x-5)^3 + (x-5)^4=5(x-5)^3(x-1)$

4 votes

Evaluate the integral: $\int\tan^5 (4x)\,\mathrm dx$.

4 votes

How is $f_{2000}$ equals $0$?

4 votes

Proving $4(a^3 + b^3) \ge (a + b)^3$ and $9(a^3 + b^3 + c^3) \ge (a + b + c)^3$

4 votes
Accepted

How to find $ \sum\limits_{n=0}^{\infty}\frac{1}{3-8n-16n^2}$?

4 votes
Accepted

Why $\arctan x \to \pi/2$ when $x \to \infty$

4 votes

Compute $\int_0^{1/2} (\arcsin(x))^2 dx$

3 votes

Proving -(a+b) = (-a) + (-b) using A1-A4 only.

3 votes

How does $\mathrm {e}^z$ and $\log z$ look like as complex functions.

3 votes

Evaluate $\int \frac{\mathrm{d}x}{x\sqrt{49x^2-1}}$

3 votes
Accepted

Arithmetic and Geometric progression question

3 votes

How can I solve $\sin(x)=\sin(2x)$?