Question

What is the name of a number that can be written in the form a+bi where a and b are nonzero real numbers?

Answer 1

the answer is complex numbers

Answer 2

We are talking about Complex numbers.

Considering
`\mathbb{C}` as the set of Complex numbers, we have

`\Bbb{C}=\{a+bi\ : a, b \in\ \Bbb{R}\}`

A complex number is a number of the form
`a+bi`

as
`i^2=-1`