Darasa la 9–12Discrete MathematicsSomo linapatikana
Combinatorics
Permutations and combinations, binomial coefficients and Pascal's triangle, the binomial theorem, the pigeonhole principle and inclusion–exclusion, with combinatorial proofs.
math.discrete.combinatorics
Inajengwa juu ya
Masharti ya awali ya lazima 15 (hadi chini kabisa)
Utajifunza
- Compute binomial coefficients and prove identities such as C(n, k) = C(n − 1, k − 1) + C(n − 1, k) by counting in two ways.
- Prove and apply the binomial theorem.
- Apply the pigeonhole principle and inclusion–exclusion to counting and existence problems.
Fasili
- C(n, k), read 'n choose k', is the number of k-element subsets of an n-element set.
- Pigeonhole principle: if more than n objects are placed in n boxes, some box contains at least two objects.
Nadharia
- C(n, k) = n!/(k!(n − k)!) for 0 ≤ k ≤ n.
- Binomial theorem: (x + y)ⁿ = Σ_{k=0}^{n} C(n, k) xᵏ yⁿ⁻ᵏ.
- Σ_{k=0}^{n} C(n, k) = 2ⁿ.
- Inclusion–exclusion: |A ∪ B ∪ C| = |A| + |B| + |C| − |A ∩ B| − |A ∩ C| − |B ∩ C| + |A ∩ B ∩ C|.
Mawazo potofu ya kawaida
- Using permutations when order does not matter.
- Thinking a pigeonhole argument must say which box contains two objects.
Inaelekea kwa
Ugunduzi wa hiari
- Enumerative combinatorics Generating functions turn counting problems into algebra.
- ← Systematic listing and counting
Njia za kujifunza
Usomaji zaidi
- Arthur Engel, Problem-Solving Strategies (1998)