Solution to $u_x + y u_y = -u$ with $u(0, y) = \cos y$
101112
Transport equation $u_t + xu_x + u = 0$ with $u(x_0, 0) = \cos(x_0)$
139474
Solving system of Congruences with Two Variables (x and y)
62211
Partial Differential Equation $U_t - (U_x)^2 = 0$
66457
Series expansion of $xy'=y$
78719
Solve the DE $yy^{\prime}+x=\sqrt{x^2+y^2}$
11707
If $x\sqrt{1+y}+y\sqrt{1+x}=0$ find $y'$
27127
Calculating $\iint (x+y) \, dx \, dy$
95774
$\frac{\partial^2 u}{\partial t^2}-c^2\frac{\partial^2u}{\partial x^2}=0\text{ implies } \frac{\partial^2 u}{\partial z \partial y}=0$
15753
Solve the following equation in positive integers $x$ and $y$
102320
Is my solution correct for solving $\cos(z)=2$, $z\in \mathbb{C}$
34435
Integral solutions to $y^{2}=x^{3}-1$
67158
Solve $y'-\int_0^xy(t)dt=2$
48039
How to solve this ode $xy''-(1+x)y'+y=x^2$?
55364
Show $au_x+bu_y=f(x,y)$ gives $u(x,y)=(a^2+b^2)^{-\frac{1}{2}}\int_{L}fds +g(bx-ay)$ if $a\neq 0$.
122705
Solution of trigonometric equation $0 = x\cos(x)+2$
129454
Solution to a quadratic form
103251
Solution(s) to $f(x + y) = f(x) + f(y)$ (and miscellaneous questions...)