absolute minimum

NOVEMBER 07, 2023

Absolute Minimum

In mathematics, the concept of absolute minimum plays a crucial role in finding the lowest point of a function or a set of data. It helps us determine the minimum value within a given range or domain. In this blog, we will explore the definition, formula, methods, and examples related to absolute minimum.

Definition

The absolute minimum of a function or a set of data refers to the lowest value that the function or data set can attain within a given range or domain. It represents the global minimum, meaning that there is no other point in the range or domain that has a lower value.

Knowledge Points

To understand the concept of absolute minimum, it is essential to have knowledge of the following:

  1. Functions: Understanding how functions work and how they can be represented mathematically.
  2. Domain and Range: Knowing the domain and range of a function, which defines the set of possible input and output values.
  3. Calculus: Familiarity with calculus concepts such as derivatives and critical points.
  4. Optimization: Understanding the process of finding the maximum or minimum value of a function.

Formula for Absolute Minimum

The formula for finding the absolute minimum of a function depends on whether the function is continuous or discrete. For continuous functions, we can use calculus techniques, while for discrete data sets, we can use methods like sorting or searching algorithms.

For continuous functions, the absolute minimum can be found by:

  1. Calculating the derivative of the function.
  2. Setting the derivative equal to zero to find critical points.
  3. Evaluating the function at these critical points and the endpoints of the domain.
  4. The lowest value among these points will be the absolute minimum.

For discrete data sets, the absolute minimum can be found by:

  1. Sorting the data in ascending order.
  2. The first element in the sorted data set will be the absolute minimum.

Applying the Absolute Minimum Formula

To apply the formula for finding the absolute minimum, follow these steps:

  1. Identify the function or data set for which you want to find the absolute minimum.
  2. Determine the domain or range within which you want to find the minimum.
  3. If dealing with a continuous function, calculate its derivative.
  4. Set the derivative equal to zero and solve for critical points.
  5. Evaluate the function at these critical points and the endpoints of the domain.
  6. The lowest value among these points will be the absolute minimum.

Symbol for Absolute Minimum

The symbol used to represent the absolute minimum is a small letter "m" with two vertical lines on either side: m.

Methods for Finding Absolute Minimum

There are various methods for finding the absolute minimum, depending on the nature of the function or data set. Some common methods include:

  1. Calculus Techniques: Using calculus concepts like derivatives, critical points, and endpoints to find the absolute minimum of continuous functions.
  2. Sorting Algorithms: Sorting the data set in ascending order and selecting the first element as the absolute minimum for discrete data sets.
  3. Optimization Algorithms: Utilizing optimization algorithms like gradient descent or simulated annealing to find the absolute minimum of complex functions.

Solved Example on Absolute Minimum

Let's consider the function f(x) = x^2 - 4x + 5 over the domain [0, 5]. To find the absolute minimum, we follow these steps:

  1. Calculate the derivative of f(x): f'(x) = 2x - 4.
  2. Set f'(x) = 0 and solve for x: 2x - 4 = 0 => x = 2.
  3. Evaluate f(x) at critical point x = 2 and endpoints of the domain: f(0) = 5, f(2) = 1, f(5) = 10.
  4. The lowest value among these points is f(2) = 1, which represents the absolute minimum.

Therefore, the absolute minimum of f(x) = x^2 - 4x + 5 over the domain [0, 5] is 1.

Practice Problems on Absolute Minimum

  1. Find the absolute minimum of the function g(x) = 3x^3 - 4x^2 + 2x - 1 over the domain [-1, 2].
  2. Determine the absolute minimum of the data set [5, 2, 7, 1, 9, 3].

FAQ on Absolute Minimum

Q: Can a function have multiple absolute minimums?

A: No, a function can have only one absolute minimum. It represents the lowest point in the entire range or domain.

Q: How is absolute minimum different from local minimum?

A: Absolute minimum refers to the lowest point in the entire range or domain, while a local minimum represents the lowest point within a specific interval or neighborhood.

Q: Is it possible for a function to have no absolute minimum?

A: Yes, if a function is unbounded below, it does not have an absolute minimum. In such cases, the function can keep decreasing indefinitely.

Q: Can the absolute minimum occur at an endpoint of the domain?

A: Yes, the absolute minimum can occur at an endpoint of the domain if the function attains its lowest value at that point.

By understanding the concept of absolute minimum and applying the appropriate formulas and methods, we can effectively find the lowest point of a function or data set. This knowledge is valuable in various fields, including optimization, data analysis, and decision-making processes.