14. Combinatorial analysis

Combinatorial Analysis is a branch of mathematics that studies the various forms of counting. It is extremely useful for solving problems involving counting, possibilities, arrangements, combinations and permutations. As it is a recurring topic in Enem tests, it is essential to understand its basic concepts and know how to apply them correctly.

To begin with, it is essential to understand the concept of factorial, represented by the symbol '!'. The factorial of a number n is the product of all positive integers from n to 1. For example, the factorial of 5 (5!) is 5*4*3*2*1 = 120. This concept is the basis for many calculations in combinatorics.

One of the main topics of combinatorics is the fundamental principle of counting. This principle states that if we have an operation that can be performed in 'm' ways, and after that we have another operation that can be performed in 'n' ways, then the total number of ways to perform the two operations is m*n . This concept is very useful for solving problems that involve multiple steps or options.

Another important concept is that of permutations. A permutation is an arrangement where the order of the elements matters. For example, permutations of 'ABC' are 'ABC', 'ACB', 'BAC', 'BCA', 'CAB' and 'CBA'. To calculate the number of permutations of n objects, we use the factorial of n (n!).

Combinations, on the other hand, are arrangements where the order of the elements does not matter. The number of combinations of n elements taken from k in k is given by the formula n!/(k!(n-k)!). This concept is useful for solving problems that involve choosing subsets of a larger set, such as choosing a team from a group of people.

In addition to these concepts, combinatorial analysis also involves the study of arrangements, which are like permutations, but where not all elements are used. The number of arrays of n elements taken from k to k is given by the formula n!/(n-k)!. This concept is useful for solving problems involving selecting and ordering subsets of a larger set.

Finally, it is important to highlight that combinatorial analysis is a powerful tool for solving complex counting problems. However, it requires a solid understanding of its basic concepts and a lot of practice to use effectively. Therefore, it is essential to study and practice regularly to be well prepared for the combinatorial analysis questions on the Enem.

In summary, combinatorics is a vast and fascinating field of mathematics with many practical applications. Your study can be challenging, but also very rewarding. With the right understanding and proper practice, you can master this topic and significantly improve your ENEM score.

Next page of the Free Ebook:

15Probability

3 minutes