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Complex numbers

Numbers of the form a + bi, where i is a number with i² = -1. They give every polynomial equation a solution.

Depth 1 · Foundation

Numbers of the form a + bi, where i is a number with i² = -1. They give every polynomial equation a solution.

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Depths of understanding

  1. 1

    Foundation

    Opens after

    Real numbersA complex number is a pair of real numbers with a new multiplication rule.

Your path here

What's still between you and Complex numbers, depth 1, in the order you can learn it.

  1. 1CountingDepth 1 · Foundation · Number Systems
  2. 2Natural numbersDepth 1 · Foundation · Number Systems
  3. 3ZeroDepth 1 · Foundation · Number Systems
  4. 4The number lineDepth 1 · Foundation · Number Systems
  5. 5AdditionDepth 1 · Foundation · Arithmetic
  6. 6MultiplicationDepth 1 · Foundation · Arithmetic
  7. 7NumeralsDepth 1 · Foundation · Number Systems
  8. 8Place valueDepth 1 · Foundation · Number Systems
  9. 9Comparing numbersDepth 1 · Foundation · Number Systems
  10. 10IntegersDepth 1 · Foundation · Number Systems
  11. 11SubtractionDepth 1 · Foundation · Arithmetic
  12. 12DivisionDepth 1 · Foundation · Arithmetic
  13. 13FractionsDepth 1 · Foundation · Fractions
  14. 14Rational numbersDepth 1 · Foundation · Number Systems
  15. 15MeasurementDepth 1 · Foundation · Measurement
  16. 16UnitsDepth 1 · Foundation · Measurement
  17. 17LengthDepth 1 · Foundation · Measurement
  18. 18Points and linesDepth 1 · Foundation · Geometry
  19. 19AnglesDepth 1 · Foundation · Geometry
  20. 20PolygonsDepth 1 · Foundation · Geometry
  21. 21TrianglesDepth 1 · Foundation · Geometry
  22. 22Parallel and perpendicular linesDepth 1 · Foundation · Geometry
  23. 23QuadrilateralsDepth 1 · Foundation · Geometry
  24. 24AreaDepth 1 · Foundation · Geometry
  25. 25AreaDepth 2 · Deeper · Geometry
  26. 26Square numbersDepth 1 · Foundation · Number Theory
  27. 27Square rootsDepth 1 · Foundation · Arithmetic
  28. 28Pythagoras' theoremDepth 1 · Foundation · Geometry
  29. 29Irrational numbersDepth 1 · Foundation · Number Systems
  30. 30Real numbersDepth 1 · Foundation · Number Systems
  31. 31Complex numbersDepth 1 · Foundation · Number Systems

Where it fits

Builds on

Real numbers

This concept

Complex numbersNumber Systems

Makes these deeper

Once you know Complex numbers, come back to these — they'll mean more.