They're used in a generalised solution to cubic equations (analogous to the quadratic solution we all learn in high school), where they represent the side lengt

They're used in a generalised solution to cubic equations (analogous to the quadratic solution we all learn in high school), where they represent the side length of a square with negative area. https://www.youtube.com/watch?v=cUzklzVXJwo https://www.youtube.com/watch?v=cUzklzVXJwo