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?

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Answer 1

Well the idea came quite naturally. Imagine youre looking to solve a quadratic equation or a cubic equation. You’ll find that a cubic equation should have 2 solutions. But sometimes you’ll only find one and the other is not solvable because you would have to take the root of a negative number. But there should be a solution says your intution. So you imagine what if there is a number i with i^2=-1. Then you could solve those negative roots. Now build a new set of numbers that includes all real numbers and those created with your newly imagined I. And it should behave like real numbers when there is no i involved. And voila you get complex numbers.