Definition and Types of limits: Explained with examples

In Mathematics, a limit is a fundamental concept that describes the behavior of a function as its input values approach a certain value or infinity. It is a way of understanding what happens to a function as input values get closer to a particular value.

Simply, the limit of the function is the value that the function approaches as its input value gets closer and closer to a certain point.

The concept of limits is important in Calculus, where it uses derivatives and integrals. It also used other areas of Mathematics like Physics, Engineering, and economics, which are used to model the behavior of the system that approaches certain limits.

Overall, limits are an essential concept in Mathematics that support many of the more advanced topics in Calculus and beyond. They require careful reasoning and attention to detail, but with practice, they can become a powerful tool for understanding the behavior of functions and sequences.

Limits are used to define important concepts in Calculus such as continuity, derivatives, and integrals. The limit of the function at a point is used to determine whether the function is continuous at that point.

In this article, we discuss the limits definition, notation, types of limits, and application of limits. 

What is a limit?

A limit is a value that a function or sequence approaches a certain value, approaches infinity or negative infinity. More formally, a limit is defined as follows:

Let f be a function defined on some interval containing a point a, except possibly at a self. We say that the limit f as x approaches a is L, denoted by

Limx→a f(t)=L

If for every Ο΅ >0, there exists a Ξ΄>0 such that if 0<|f(x)-L|< Ο΅.

This definition means that as x is closer to a, f(x) gets arbitrarily close to L. The value of L is a limit that exists, it may be not equal to the toe value of the function.

Notation of limits

In mathematics, limits are a fundamental concept that describes the behavior of a function as the input approaches a certain value. The notation used to represent limits is as follows:

The limit of a function f(x) as x approaches a is denoted by: 

  limxβ†’a f(x)=L

This means that as x gets closer and closer to the value of a (from both sides), the values of f(x) get closer and closer to L.

The limit of a function f(x) as x approaches infinity is denoted by:

Limxβ†’βˆž f(x)=L

This means that as x becomes larger and larger, the values of f(x) approach the value of L.

Types of limits

Several types of limits can be classified based on the behavior of the function as the input approaches a certain value. The most common types of limits are:

  • Finite limit
  • Infinite limit
  • One-sided limit
  • Oscillating Limit
  • Discontinuous limit

Here is a brief introduction to the types of limits.

1.     Finite Limit

If a function approaches a finite number as the input approaches a certain value, the limit is called a finite limit. In other words, the value of the function gets arbitrarily close to a specific number but never equals that number.

Finite limits play important role in Calculus and other branches of Mathematics, as they allow us to study the behavior of functions near certain points and make precise statements about their properties.

2.     Infinite Limit

 If a function approaches infinity or negative infinity as the input approaches a certain value, the limit is called an infinite limit. In other words, the value of the function grows without bounds or becomes increasingly negative as the input gets closer to the limiting value.

3.     One-sided Limit

 If a function approaches a different value from the left and from the right as the input approaches a certain value, the limit is called a one-sided limit. In other words, the left-hand and right-hand limits are not equal.

One-sided limits are useful in analyzing the behavior of functions near certain points, such as points of discontinuity or vertical asymptotes. They also play important in the definition and application of the derivative in Calculus.   

4.     Oscillating Limit

If a function oscillates between two or more values as the input approaches a certain value, the limit does not exist.

One example of an oscillating limit is the limit of the function sin(1/x) as x approaches zero. As x approaches zero from either side, the value of sin(1/x) oscillates between -1 and 1, and the limit does not exist. 

5.     Discontinuous Limit

 If a function has a jump discontinuity or infinite discontinuity at the limiting value, the limit does not exist. In other words, the function either has a sudden change in value or becomes infinite at the limiting value.

Discontinuous limits can pose challenges in Calculus and other areas of Mathematics, as they can make it difficult to make precise statements about the behavior of functions near certain points.

How to find the limit?

Limits are a fundamental concept in calculus, and they are used to describe the behavior of a function as the input values approach a certain value. Let us take a few examples to find the limit of the given function at a particular point.

Example 1

Find the limit of the given function limx→2 4x3=?

Solution:

Step 1: Take the coefficient outside the limit notation

limx→2 4x3= 4 limx→2 x3

Step 2: Apply the power rule of limit.

limx→2 4x3= 4[limx→2 (x)]3

limx→2 4x3= 4[2]3

limx→2 4x3= 4[8]

limx→2 4x3= 32

Example 2

Find the limit of the given function limx→1 (2x/x+4) =?

Solution:

Step 1: Use the quotient and sum rules of limits.

limx→1 (2x/x+4) = limx→1 (2x) / limx→1 (x + 4)

limx→1 (2x/x+4) = limx→1 (2x) / [limx→1 (x) + limx→1 (4)]

Step 2: Take the coefficient outside the limit notation

limx→1 (2x/x+4) = 2limx→1 (x) / [limx→1 (x) + limx→1 (4)]

Step 3: Apply the specific point x = 1.

limx→1 (2x/x+4) = 2 (1) / [(1) + (4)]

limx→1 (2x/x+4) = 2/5

Conclusion

In this article, a basic definition of limits and their formulas and types of limits are discussed. Moreover, with the help of examples, the topic is explained. After a complete understanding of this article, anyone can defend this topic.

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