Question

what is a special complex number?

Answer 1

hint:
a complex number is a number in this form:
\[\Large a + ib\]
where a, and b are real numbers

Answer 2

and i is such that
\[\Large {i^2} = - 1\]

Answer 3

when a=0 the complex number is purely imaginary

Answer 4

when b=0, the complex number is a real number,

real, and purely imaginary numbers, are special cases of the more general complex numbers