Showing expression of $dA$ in cartesian coordinates = $dA$ in cylindrical polar
6843
Explain $\iint \mathrm dx\,\mathrm dy = \iint r \,\mathrm \,d\alpha\,\mathrm dr$
86193
Rigorous proof that $dx dy=r\ dr\ d\theta$
1932
How to show this equality of $\rho(X,Y)$
33100
Trigonomnetric equality involving tg
49984
Valid justification for algebraic manipulation of $\mathrm{d}y/\mathrm{d}x$?
9539
$\alpha$ and $\beta$ are solution of $a \cdot \tan\theta + b \cdot \sec\theta = c$ show $ \tan(\alpha + \beta) = \frac{2ac}{a^2 - c^2}$
127711
Evaluating $\int_{0}^{1}\int_{0}^{1}\sqrt{x^{2}+y^{2}}dxdy$ using polar coordinates.
83359
Complex number identity by trigonometry
141643
Showing $\rho (x,y)=\frac{d(x,y)}{1+d(x,y)}$ is a metric
105774
How is $ \cos (\alpha / \beta) $ expressed in terms of $\cos \alpha $ and $ \cos \beta $?
114411
Simple Proof of the Euler Identity $\exp{i\theta}=\cos{\theta}+i\sin{\theta}$
16443
Laplacian in polar coordinates
93875
"Show" that the direction cosines of a vector satisfies...
54512
How do I prove: $\cos (\theta + 90^\circ) \equiv - \sin \theta $
100901
Proof of centripetal acceleration formula ($a_c = v^2/r$) for non-uniform circular motion
120841
Solving the Helmholtz equation in polar coordinates
153422
How to find the corrsponding expression after working with natural units $\hbar=c=1$?