4. Complex numbers are defined around the number

6. Technically abstract use Many things in real life can be modeled with polynomials Polynomials are equations with to powers Examples of polynomials:

8. Concrete use Complex numbers sometimes used to model vectors Sometimes used just to simplify work As long as you don’t end up with 4i of anything in the real world, you’re okay

10. Concrete use Processing sound, images, and medical data

12. Concrete use Used to determine stability of a dynamic system (i.e. populations of wildlife)

14. Abstract use Physics of electricity and magnetism

16. Technically concrete use Schrodinger’s wave function describes the behavior of electrons with i

18. Concrete use Study of maps and mapmaking

20. Concrete use Study of vibration

22.  Concrete use  Used to shape the airfoil of a plane wing