why is $\dfrac{dr}{r~d\theta} = \cot \psi$?
31102
Why does $\frac{1}{r}\frac{dr}{d\theta} = \cot \psi$?
158235
Laurent Series for $\cot(\pi z)$
122556
Integral $\int\!\sqrt{\cot x}\,dx $
93539
Why is $M\frac{dv}{dt} = v_{rel} .\frac{dm}{dt}$ correct and $(M - dm)\frac{dv}{dt} = v_{rel} .\frac{dm}{dt}$ wrong?
85984
How come $\frac{\partial(\partial_{\beta}A_{\gamma})}{\partial(\partial_{\mu}A_{\nu})} = g_{\beta\mu}g_{\gamma\nu}$?
18564
Why is the symmetry variation $\delta_s q$ different from the ordinary variation $\delta q$?
126236
General closed form of $\int_{0}^{\theta_0} \frac{1}{\sqrt{\cos \theta-\cos \theta_0}} d\theta$
29064
Can the real and imaginary parts of $\dfrac{\sin z}z$ be simplified?
63952
Disproving: If $(\Gamma\vdash(\phi\,\lor\psi))$, either $(\Gamma\vdash\phi)$ or $(\Gamma\vdash\psi)$ is true
73099
Why is $d(x^2)= 2xdx$?
35454
Is it correct to write $\Bbb E[X]$ or $\Bbb E_{\theta}[X]$?
113612
Why does $P(\theta_1\mid D, \theta_2) \propto P(D \mid \theta_1, \theta_2)P(\theta_1)$ hold?
33791
Is it generally true that $\arcsin \theta + \arccos \theta = \frac{\pi}{2}$?
133756
Geometric interpretation of $\det(A^T) = \det(A)$
130253
Differentiating $\mbox{tr} (ABA^TC)$ w.r.t. $A$
113080
Prove $\tan\big(\frac{\pi}{2} -\theta \big) = \cot \theta$
109159
What's the intuition behind $(\exists y)(\mathscr{C}(y)\supset\mathscr{D})\supset((\forall x)\mathscr{C}(x)\supset\mathscr{D})$