Advanced Combinatorics and Pascal's Triangle
This page delves deeper into combinatorial concepts, focusing on combinations and their properties. It introduces binomial coefficients and explores the famous Pascal's Triangle.
Combinations are defined as unordered selections from a set, contrasting with arrangements where order matters. The number of combinations of p elements from a set of n elements is given by the formula:
Formula: C(n,p) = n! / (p! * (n-p)!)
This is also known as the binomial coefficient, often denoted as (n choose p) or nCp.
Highlight: Unlike arrangements, the order of elements doesn't matter in combinations.
The page then introduces Pascal's Triangle, a triangular array of binomial coefficients that reveals several interesting properties:
- Symmetry: C(n,p) = C(n,n-p)
- Sum of row elements: The sum of elements in the nth row equals 2^n
- Construction: Each number is the sum of the two numbers directly above it
Example: In Pascal's Triangle, the 4th row (starting from 0) is 1 4 6 4 1, representing C(4,0), C(4,1), C(4,2), C(4,3), and C(4,4) respectively.
The document also touches on the concept of subsets, stating that for a set with n elements, the total number of subsets is 2^n.
Vocabulary: A subset is a set whose elements are all members of another set.
This page provides crucial information for students studying combinatoire et dénombrement Terminale exercices corrigés, offering a comprehensive look at combinations and their applications in advanced mathematics and probability theory.