šÆUnderstand Proof by Induction: The Domino Argument That Works
Build intuition for mathematical induction through the domino analogy and concrete number examples, then prove classic identities and write your own induction proof from scratch.
Phase 1The Domino Setup
See why the domino argument actually works
Knock one domino down and trust the chain
6 minKnock one domino down and trust the chain
Skip the base case and you can prove anything
7 minSkip the base case and you can prove anything
Assume it works, then prove it still works one step later
7 minAssume it works, then prove it still works one step later
Three ways to write a proof that proves nothing
7 minThree ways to write a proof that proves nothing
Phase 2Proving Classic Identities
Prove classic identities step by step
Stack squares into a pyramid and count the blocks
7 minStack squares into a pyramid and count the blocks
Multiply by r and watch terms cancel like magic
6 minMultiply by r and watch terms cancel like magic
Proving that 2āæ grows faster than n² ā and when it starts
7 minProving that 2āæ grows faster than n² ā and when it starts
Prove that n³ ā n is always divisible by 6
7 minProve that n³ ā n is always divisible by 6
Pin down Fibonacci growth with a two-step induction
8 minPin down Fibonacci growth with a two-step induction
Phase 3Induction in the Wild
Compare weak, strong, and structural induction
When one predecessor isn't enough
7 minWhen one predecessor isn't enough
Trees aren't numbers ā but induction still works on them
7 minTrees aren't numbers ā but induction still works on them
Spot the bug before it infects the theorem
7 minSpot the bug before it infects the theorem
Weak, strong, or structural ā pick the right induction
7 minWeak, strong, or structural ā pick the right induction
Phase 4Your Own Proof
State and prove your own induction claim
State a claim, build the dominoes, push the first one
8 minState a claim, build the dominoes, push the first one
Frequently asked questions
- Why is the base case necessary?
- This is covered in the āUnderstand Proof by Induction: The Domino Argument That Worksā learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- What is the difference between weak and strong induction?
- This is covered in the āUnderstand Proof by Induction: The Domino Argument That Worksā learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- Can induction prove something false if the base case is wrong?
- This is covered in the āUnderstand Proof by Induction: The Domino Argument That Worksā learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
- When should I use structural induction?
- This is covered in the āUnderstand Proof by Induction: The Domino Argument That Worksā learning path. Start with daily 5-minute micro-lessons that build from fundamentals to hands-on application.
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