Find a change of variables that shifts this problem from [-4, 4] to [0, 8] :

PDE: u_t = 5u_xx for all -4 < x < 4 and t > 0

Boundary Conditions: u (t, -4) = u (t, 4) = 0 for all t > 0

Initial Condition: u (0, x) = f(x) for all -4 < x < 4

where

f(x) = x, -2 < x <2

0 otherwise

I am trying to figure out how to shift this problems boundary conditions from [-4, 4] to [0, 8] and am stuck. Thanks!