June 20th, 2007, 12:26 pm
QuoteOriginally posted by: ntruwantHicould anybody help me with exp(ix) where i²=-1. Can you tell that it is 0 at x=+infinity and x=-infinity and why?since we're dealing with complex numbers, let's write x=x_r + i x_i where x_r and x_i are the real and imaginary parts of xexp(i x) =exp(i x_r) exp(i^2 x_i) =(cos x_r + i sin x_r) exp(-x_i) x -> "infinity"if the imaginary part of x is > 0, exp(ix) will vanish as x -> "infinity"