How do I differentiate
f(x,t) = expi(kx-wt)
f'(x,t) = ?
f''(x,t) = ?
What do your primes denote differentiation with respect to?
Write your expression as exp(ikx).exp(-iwt). Depending upon what you are differentiating with respect to, one of these terms can be treated as a constant. You know how to differentiate exp(x), right?
Does it make a difference if "i" is involved?
Separate names with a comma.