No.Suppose bi and di are two complex purely imaginary numbers such that b and d are real.Thenbi * di = bdi2 = -bd which is real.
If y = a + bi and z = c + di are two complex numbers then z - y = (c - a) + (d - b)i
di means two
"Di" means two.
di itself is a prefix meaning two.
The prefix di means two. For example, carbon dioxide is a molecule with two oxygen atoms; di + oxygen = dioxide.
'di' is a prefix, not a suffix, and it means 'two'
Lago di Garda Lago di Como
The prefix "di-" signifies two. An example being "diverse."
The word 'di' means two. In a carbon dioxide molecule there is one atom of carbon and two atoms of oxygen. Thus the di-oxide means two atoms of oxygen.