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Lesson 4 of 20 · about 15 min

Infinity and countability

Some infinities are bigger than others. Using bijections from lesson 2, you'll see why there are exactly as many even numbers as whole numbers, why fractions can be listed one by one, and why the real numbers can't, using one of the most beautiful arguments in mathematics.

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In this lesson you'll learn:

  • Countable
  • Cantor's diagonal argument

Free to try in F06 Discrete Math:

The first 3 lessons of every course are free, no account needed.