I wanted to but I'm not an active user of MSE or any social media.

My old account

Back then when I used to answer with explanations

How to evaluate the integral $I = \int_o^{\infty} \frac{x}{\sqrt{e^{2\pi\sqrt{x}}-1}}dx$?

In an attempt to find $I = \int_0^\infty \frac{t}{e^t-1}dt$

$\frac {\zeta(2)}{e^2} + \frac {\zeta(3)}{e^3} + \frac {\zeta(4)}{e^4} + \frac {\zeta(5)}{e^5}.....?$

How $\phi(2)$ comes into the picture?

Various ways to calculate $\int \sin(x) \cos(x) \, \mathrm{d}x$

$\sum _{k=1}^n\:\left(\cos\left(\frac{2\cdot k\cdot \pi }{n}\right)-2\:+\:i\cdot \sin\left(\frac{2\cdot k\cdot \pi }{n}\right)\right)$

Prove that $\log_27×\log_29<9$

If $f\left(\pi\right)=\pi$ and $\int_{0}^{\pi}\left(f\left(x\right)+f''\left(x\right)\right)\sin x\ dx\ =\ 7\pi$ then find $f\left(0\right)$

To find the $n$th term of a Geometric progression.

Find the value of $c$ such that $\lim_{x\to\infty} \frac{1+ce^x}{\sqrt{1+cx^2}} = 4$

Sorry for being rude with these Short answers!

Crazy $\int_0^{\frac\pi{2}}\frac {\cos\left((1-2n)\arcsin\left(\frac{\sin(\theta)}{\sqrt 2}\right)\right)}{\sqrt{1-\frac{\sin^2 \theta}{2}}}d\theta$

https://math.stackexchange.com/questions/4296567/does-this-series-converge-sum-n-3-infty-frac3n-43n2-fracn13/4296596#4296596

How can I find the formula for the integral $ \int_{0}^{\infty} \frac{x^{n}\left(e^{3 x}-e^{x}\right)}{\left(e^{x}-1\right)^{4}} d x ? $ where $n>2$.

Show that $\sum_{2}^{n} (k^2-k)=\frac{n^3-n}{3}$

Few of my favorites

Which of the two quantities $\sin 28^{\circ}$ and $\tan 21^{\circ}$ is bigger .

Derivative of ${g(x)=\int_0^1 \frac{e^{-x^2(t^2+1)}}{t^2+1}\,dt}$ respect to $x$.

Curvature as a rate of change in slope

2015 Cambridge Entrance Examination Q6

More general Frullani's

Sum of Squares of Harmonic Numbers

Trying to prove $\left(1-\frac13+\frac15-\frac17+\cdots\right)^2=\frac38\left(\frac1{1^2}+\frac1{2^2}+\frac1{3^2}+\frac1{4^2}+\cdots\right)$

Representing the cyclic differentiation pattern of $\frac{d^n}{dx^n}(\sin(x))$ using linear algebra.