Maybe it's u(w,0) = x+6. But can you please tell me where my mistake is? Also, HOW did you get u(w,0) = x+6?

We know u(x,0) = x+5
=> u(w,0) = w+5 ?
I believe the logic in this step cannot be wrong, consider e.g. f(4z)=cos(4z), now how do we find f(4z-y)? Of course, f(4z-y)=cos(4z-y). How do we find f(z)? Surely, f(z)=cos(z). Right??


u(w,0)
= u(x-1,0) = (x-1)+5
=> u(w,0) = w+5 ?