how to get $dx\; dy=r\;dr\;d\theta$
6843
Explain $\iint \mathrm dx\,\mathrm dy = \iint r \,\mathrm \,d\alpha\,\mathrm dr$
49073
how to obtain solution for $u_t+u=u_{xx}$
62140
Direction of $d\mathbf{l}$
137550
Finding the derivatives of inverse functions at given point of c
67158
Solve $y'-\int_0^xy(t)dt=2$
144978
Find the differential equation of all circles of radius a
38839
Exponential of the differential operator
33118
How can I plot the direction field for a differential equation?
80471
Derivative of $(y-XB)' h(y-XB)$ with respect to $B$
133847
Derivative of determinant of a matrix
142892
Lagrangian Mechanics - Commutativity Rule $\frac{d}{dt}\delta q=\delta \frac{dq}{dt} $
104489
Derivative (or differential) of symmetric square root of a matrix
151471
Equation of a sphere as the determinant of its variables and sampled points
3092
Find where $r(t)=$ hits the $x-y$ plane
81533
Integrating $\int_1^2 \int_0^ \sqrt{2x-x^2} \frac{1}{((x^2+y^2)^2} dydx $ in polar coordinates
40805
Solve $u_t=u_{xx}+u_x$
100487
How to derive relation for time derivative in a rotating reference frame