$5/$ The energy equation in two dimensions boundary layer flow, with constant density and $1$ developed velocity profile

$u\frac{\text{d}\text{e}\text{l}\text{T}}{\text{d}\text{e}\text{l}\text{t}}=\frac{}{Pr}\frac{de{l}^{2}T}{del{y}^2}$

Is it parabolic or elliptic, why?

Write it in finite difference explicit form.

Write it in Crank Nicolson method

$(12$ Ma