How did imaginary numbers come into existence? What was the first problem that required use of imaginary number?

Question

How did imaginary numbers come into existence? What was the first problem that required use of imaginary number?

In: 760

Answer 1

The same problems that they are used for now: square roots of negative numbers.

There are many problems in physics where you do have to ha square root of a negative number as part of the process of finding out the answer even if that itself will never ultimately be the answer.