Hey! :o
I have to solve the following pde:
$$u_{tt}(x, t)-u_{xt}(x, t)=0, x \in \mathbb{R}, t>0 \\ u(x, 0)=f(x), x \in \mathbb{R} \\ u_t(x, 0)=g(x), x \in \mathbb{R}$$
I have done the following:
$$\Delta(x, t)=1>0$$
so it is an hyperbolic equation.
We want to write the equation into...