x=1+2I
y=3+4I

x+y  =>  4 + 6 I
x-y  =>  -2 - 2 I
y x  =>  -5 + 10 I
y/x  => 11/5 - (2 I)/5
x^3  =>  -11 - 2 I
y^4  =>  -527 - 336 I
x^y  =>  (1 + 2 I)^(3 + 4 I)
N[x^y]  =>  0.12901 + 0.0339241 I