## Proof by Exhaustion: A Detailed Guide for A-Level Maths

### Hey readers,

Welcome to our comprehensive guide on Proof by Exhaustion for A-Level Maths. This exhaustive method can be a game-changer for solving certain problems, and we’re here to explain it in a way that’s both thorough and easy to understand. Let’s dive right in!

## What is Proof by Exhaustion?

Proof by Exhaustion is a mathematical technique used to prove a statement by considering every possible case. This method is particularly useful when the number of cases is limited and manageable. Essentially, you check each case one by one to demonstrate that the statement holds true for all of them.

## When to Use Proof by Exhaustion

Proof by Exhaustion is most effective when the following conditions are met:

- The problem involves a finite number of cases.
- The cases can be classified into a limited number of categories.
- The statement can be verified for each case individually.

## Steps Involved in Proof by Exhaustion

To apply Proof by Exhaustion effectively, follow these steps:

**List all possible cases:**Identify and list every possible case that falls under the given conditions.**Examine each case individually:**For each case, check if the statement holds true.**Draw a conclusion:**Based on the results of your examination, determine whether the statement is true for all cases.

## Sections in a Proof by Exhaustion

A well-structured Proof by Exhaustion typically includes the following sections:

### Introduction

- Purpose of the proof
- Statement to be proved

### Case Analysis

- List of all possible cases
- Examination of each case

### Conclusion

- Summary of the results
- Statement of the conclusion

## Table: Examples of Proof by Exhaustion

Problem | Cases | Verification | Result |
---|---|---|---|

Prove that the sum of two odd numbers is even. | Odd numbers: 2n+1 and 2m+1 | (2n+1) + (2m+1) = 2(n+m+1) | Sum is even |

Determine the number of sides of a regular polygon with interior angle sum of 360°. | Possible sides: 3, 4, 5, 6, 7, 8, 9, 10 | (n-2) * 180° = 360° | n = 3 (triangle) |

Show that the equation x² – 3x + 2 = 0 has no real solutions. | Possible factors: (x-1), (x-2) | x² – 3x + 2 ≠ 0 | No real solutions |

## Conclusion

That’s it for our guide to Proof by Exhaustion, readers! This method can be a powerful tool for solving A-Level Maths problems when other methods fail. Remember, the key is to be thorough in your case analysis and to consider every possibility.

If you’d like to delve deeper into mathematical concepts, check out our other articles on topics like Calculus, Algebra, and Statistics. Keep exploring and keep solving those equations!

## FAQ about ‘Proof by Exhaustion’ in A Level Maths

### What is proof by exhaustion?

Proof by exhaustion involves considering all possible cases of a statement and proving that each case is true.

### When is proof by exhaustion used?

Proof by exhaustion is typically used when the number of cases to consider is finite.

### Give an example of proof by exhaustion.

To prove that the sum of the first n natural numbers is n(n+1)/2, we would need to prove this for n=1, n=2, n=3, and so on.

### What are the steps involved in proof by exhaustion?

- List all possible cases.
- Prove that each case is true.
- Conclude that the statement is true for all cases.

### What are the limitations of proof by exhaustion?

Proof by exhaustion is only valid when the number of cases is finite.

### Can proof by exhaustion be used to prove statements about infinite sets?

No, proof by exhaustion cannot be used to prove statements about infinite sets, as there are an infinite number of cases to consider.

### What is the difference between proof by exhaustion and proof by contradiction?

Proof by exhaustion proves a statement by considering all possible cases, while proof by contradiction proves a statement by assuming its negation is false and deriving a contradiction.

### What are the advantages of proof by exhaustion?

Proof by exhaustion is a straightforward and often easy to implement method of proof.

### What are the disadvantages of proof by exhaustion?

Proof by exhaustion can be tedious and time-consuming when the number of cases is large.