General Solutions for Trivial High Order PDEs

[nick_ee]

I should find the general solution of the two following trivial PDEs.

$$u=u(x_1,x_2,...,x_n)$$

1)

$$\frac{\partial u}{\partial x_1 \partial x_2} = 0$$

2)

$$\frac{\partial u}{\partial x_1} - u = 0$$

 

[antibrane]

What in particular are you having trouble with?

 

[Mark44]

What have you tried? Per forum rules, you need to show some effort at solving the problem.