User Riemann'sPointyNose

37 votes

Is there a reason it is so rare we can solve differential equations?

answered Aug 7, 2020 at 0:36

15 votes

Accepted

$\int_0^{\infty} \arctan{\left(\frac{n}{\cosh{(x)}}\right)} \mathop{dx}$

answered Jul 4, 2020 at 20:01

12 votes

Why is $x^{x^x}=x^{x x}=x^{x^2}=x^{2x}$ wrong?

answered Aug 8, 2020 at 20:39

9 votes

Another way to solve $\int \frac{\sin^4(x)}{1+\cos^2(x)}\ dx$ without the substitution $y=\tan\left(\frac{x}{2}\right)$?

answered Jul 9, 2020 at 20:34

8 votes

Accepted

Evaluating $\int_{0}^{2\pi}\frac{1}{\cos^2(\theta)+1}\, d\theta$

answered Jul 17, 2020 at 23:02

8 votes

Can the integral $\int e^{dx}$ be solved?

answered May 20, 2021 at 21:27

7 votes

Accepted

Can $y=10^{-x}$ be converted into an equivalent $y=\mathrm{e}^{-kx}$?

answered Jul 22, 2020 at 0:49

7 votes

Solving trigonometric equations: $\cos(3x)+ \cos(x)=0$

answered Jun 22, 2020 at 0:15

7 votes

Accepted

Difference between $\mathbb{R}^1$ and $\mathbb{R}$

answered May 2, 2021 at 20:35

6 votes

Accepted

What type of differential equation is $f'(x) = f(x/2)$ and how do you solve it?

answered Jun 13, 2020 at 0:32

6 votes

How can someone reject a math result if everything has to be proved?

answered Jul 23, 2020 at 14:48

6 votes

Accepted

Evaluating $\lim_{\beta\to 0^-} \left(-\ln|\beta| + e^{\beta}\right) + \lim_{\beta\to 0^+} \left(\ln|\beta|\right)$?

answered Jan 27, 2021 at 1:55

6 votes

Accepted

Is the summation $\sum_{i=1}^{n}\frac1{i} \binom{n}{i}$ possible?

answered Aug 4, 2020 at 20:52

6 votes

Evaluate $3\int_{0}^{2\pi} \sin(t) \cos(t) \,{\rm d}t$

answered Aug 25, 2020 at 14:36

5 votes

Integrate $\frac{\theta \sin \theta}{1+\cos^2 \theta}$ with respect to $\theta$

answered Jul 19, 2020 at 22:19

5 votes

Solving $\int_{-\infty}^{\infty} \frac{x\sin(3x)}{x^4+1}\,dx $ without complex integration

answered Jul 4, 2020 at 19:19

5 votes

Is transformation (sinx,cosx) linear?

answered Jul 25, 2020 at 14:38

5 votes

Accepted

Where does the integration end?

answered Aug 16, 2020 at 19:12

5 votes

how to prove that $\lim_{j \rightarrow \infty} \ln\left(\frac{j^2+1}{j+1}\right) = \infty$?

answered Feb 27, 2021 at 21:04

5 votes

Why does $\int_{-1}^{1}\frac{dx}{\sqrt{-x^2+1}} = \pi$?

answered Jan 25, 2021 at 17:09

5 votes

The set of positive real numbers is closed under addition, multiplication, and division

answered Feb 4, 2022 at 18:29

5 votes

All groups $(G, \cdot)$ such that $\forall g_1, g_2 \in G, g_1,g_2 \in G \iff g_1 \cdot g_2 \in G$?

answered Jul 30, 2022 at 20:55

4 votes

Accepted

Indefinite integral of $\sin^8(x)$

answered Jul 29, 2020 at 17:19

4 votes

Prove by induction $1 + z + z^2 + .... +z^n = \frac{z^{n+1}-1}{z-1}$ for $z \neq$ 1

answered Aug 1, 2020 at 0:17

4 votes

Accepted

Solve the initial value problem: $\frac{dy}{dx} = e^{x+y}$, given $y(0)=0$.

answered Jul 23, 2020 at 20:18

4 votes

Accepted

Why is it true that if the integral is finite then $\lim_{s\to\infty} \int_{s}^{\infty} f(x) dx=0$?

answered Jul 7, 2020 at 22:39

4 votes

Accepted

Does ${f(x)=\ln(e^{x^2})}$ reduce to ${x^2\ln(e)}$ or ${2x\ln(e)}$?

answered Jul 22, 2020 at 16:44

4 votes

complex numbers equation with 3rd power

answered Jun 12, 2020 at 22:15

4 votes

Accepted

Partial derivative of $f(x,y)= \int_{x}^{y}e^{t^-2}dt$

answered Jun 18, 2020 at 19:56

4 votes

Accepted

Prove that if $p_1,...,p_k$ are distinct prime numbers, then $\sqrt{p_1p_2...p_k}$ is irrational

answered Jun 29, 2020 at 22:40

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192 Answers

Is there a reason it is so rare we can solve differential equations?

$\int_0^{\infty} \arctan{\left(\frac{n}{\cosh{(x)}}\right)} \mathop{dx}$

Why is $x^{x^x}=x^{x x}=x^{x^2}=x^{2x}$ wrong?

Another way to solve $\int \frac{\sin^4(x)}{1+\cos^2(x)}\ dx$ without the substitution $y=\tan\left(\frac{x}{2}\right)$?

Evaluating $\int_{0}^{2\pi}\frac{1}{\cos^2(\theta)+1}\, d\theta$

Can the integral $\int e^{dx}$ be solved?

Can $y=10^{-x}$ be converted into an equivalent $y=\mathrm{e}^{-kx}$?

Solving trigonometric equations: $\cos(3x)+ \cos(x)=0$

Difference between $\mathbb{R}^1$ and $\mathbb{R}$

What type of differential equation is $f'(x) = f(x/2)$ and how do you solve it?

How can someone reject a math result if everything has to be proved?

Evaluating $\lim_{\beta\to 0^-} \left(-\ln|\beta| + e^{\beta}\right) + \lim_{\beta\to 0^+} \left(\ln|\beta|\right)$?

Is the summation $\sum_{i=1}^{n}\frac1{i} \binom{n}{i}$ possible?

Evaluate $3\int_{0}^{2\pi} \sin(t) \cos(t) \,{\rm d}t$

Integrate $\frac{\theta \sin \theta}{1+\cos^2 \theta}$ with respect to $\theta$

Solving $\int_{-\infty}^{\infty} \frac{x\sin(3x)}{x^4+1}\,dx $ without complex integration

Is transformation (sinx,cosx) linear?

Where does the integration end?

how to prove that $\lim_{j \rightarrow \infty} \ln\left(\frac{j^2+1}{j+1}\right) = \infty$?

Why does $\int_{-1}^{1}\frac{dx}{\sqrt{-x^2+1}} = \pi$?

The set of positive real numbers is closed under addition, multiplication, and division

All groups $(G, \cdot)$ such that $\forall g_1, g_2 \in G, g_1,g_2 \in G \iff g_1 \cdot g_2 \in G$?

Indefinite integral of $\sin^8(x)$

Prove by induction $1 + z + z^2 + .... +z^n = \frac{z^{n+1}-1}{z-1}$ for $z \neq$ 1

Solve the initial value problem: $\frac{dy}{dx} = e^{x+y}$, given $y(0)=0$.

Why is it true that if the integral is finite then $\lim_{s\to\infty} \int_{s}^{\infty} f(x) dx=0$?

Does ${f(x)=\ln(e^{x^2})}$ reduce to ${x^2\ln(e)}$ or ${2x\ln(e)}$?

complex numbers equation with 3rd power

Partial derivative of $f(x,y)= \int_{x}^{y}e^{t^-2}dt$

Prove that if $p_1,...,p_k$ are distinct prime numbers, then $\sqrt{p_1p_2...p_k}$ is irrational