The symbol ii represents the square root of -1.
i1 : z = 3-4*ii o1 = 3 - 4ii o1 : CC
i2 : z^5 o2 = - 237 + 3116ii o2 : CC
i3 : 1/z 3 4 o3 = -- + --*ii 25 25 o3 : CC
Here are some functions for use with complex numbers.
See also numbers.