What is the Limit in Mathematics? – Types & Examples

Limit in Mathematics – In the field of mathematics, the concept of limits is crucial in calculus and other related branches. Limits serve as the foundation for understanding continuity, derivatives, and integrals, making it an essential concept in mathematics. 

When an input value or index gets close to a certain value, a function or sequence approaches that value, which is characterized as a limit. Essentially, a limit refers to the value that a function approaches as its input approaches a specific point. A limit specifies how a function behaves as it gets closer to a particular value. 

What is the Limit in Mathematics

When dealing with complex functions or functions that have different behaviors from the left and right sides of a given point, one-sided limits and other types of limits become essential. In this article, we will elaborate on a comprehensive explanation of limits, exploring their definitions, types, significant results, and examples. 

Definition of a Limit: 

A limit is a fundamental concept that describes the behavior of a function as the input value approaches a particular point. In mathematics, the limit of a function f(x) as x approaches a specific value c is denoted as: 

Limxàc f(x) = L 

The above expression signifies that we are observing the behavior of the function f(x) as the input value “x” gets closer and closer to “c”. The limit represents the value that f(x) approaches as “x” approaches “c”. This notation indicates that we are interested in the behavior of the function “f(x)” as “x” gets closer and closer to “c.” 

When evaluating a limit, we consider what happens to the function as x comes closer and closer to c, but not necessarily reaching c itself. This notion of “approach” is fundamental as it allows us to analyze functions that may exhibit complex behavior at c without actually evaluating the function at that point. 

Types of Limits:

Limits can fall into several categories, depending on the behavior of the function as x approaches c, which is a specific point. There are various types of limits encountered in mathematics. Some common types include: 

1. One-Sided Limits: 

A one-sided limit refers to the behavior of a function as the input approaches from only one side of the specific point. Mathematically, 

limxàc⁺ f(x) & limxàc⁻ f(x) 

One-sided limits allow us to explore these distinct behaviors. 

• Left-Hand Limit: 

The left-hand limit of a function as “x” approaches “c” from the left side, denoted as: 

limxàc⁻ f(x)  

This limit examines the behavior of the function when “x” approaches “c” from values that are less than “c.” 

• Right-Hand Limit:  

Conversely, the right-hand limit of a function as “x” approaches “c” from the right side is denoted as: 

limxàc⁺ f(x)  

This limit focuses on the behavior of the function as “x” approaches “c” from values that are greater than “c.” 

• Evaluating One-Sided Limits:  

To evaluate one-sided limits, we analyze the function’s behavior as it approaches the specified value from the left or the right. 

• Approaching from the Left:  

When evaluating the left-hand limit, we examine the function’s values as “x” approaches “c” from the left side. 

• Approaching from the Right:  

Conversely, when evaluating the right-hand limit, we observe the function’s values as “x” approaches “c” from the right side. 

• Determining Existence:  

For a one-sided limit to exist, the function’s values from the left or right must approach a finite number as “x” approaches “c.” If the function’s values become infinitely large or tend to different values from the left and right, the one-sided limit does not exist. 

1. Finite Limits:  

If the limit of a function is a real number (numerical value), it is called a finite limit. 

1. Infinite Limits: 

An infinite limit occurs when the value of the function approaches positive or negative infinity (± ∞) as the input approaches a particular value. 

Limxàc f(x) = ± ∞ 

1. Limit at Infinity: 

The limit at infinity represents the behavior of the function as the input value becomes extremely large or small. 

Limxà ∞ f(x) and limxà – ∞ f(x) 

Important Results: 

Here we will present some important deductions to remember that are employed during the computation of limit problems. 

• Lim n à + ∞ (1 + 1/n)^n = e 
• Lim x à 0 [(e^x – 1) / x] = loge e = 1 
• Lim x à 0 [(a^x – 1) / x] = loge a  
• Lim x à 0 (1 + x)^1/x = e 

• Lim x à – ∞ e^x = Limxà – ∞ (1/e^-x) = 0 
• Lim x à ± ∞ (a/x) = 0, where a is any real number. 
• Lim θà 0 sin θ/ θ = 1 if θ is measured in radian. 

How to find the limit value?

You can find the limit value with the help of laws and types of limit calculus manually. 

Example 1: 

Express the limit in terms of the number ‘e’ Limxà + ∞ (1 + 3/n)^2n. 

Solution:  

Step 1: Given data 

Limxà + ∞ (1 + 3/n)^2n 

 Step 2: Compare the required problem with the following result. 

Lim n à + ∞ (1 + 1/n)^n = e 

Step 3: Now  

(1 + 3/n)^2n = [(1 + 3/n)^n/3]^6 = [(1 + 1/n/3)^n/3]^6  

Limxà + ∞ (1 + 3/n)^2n = Limxà + ∞ [(1 + 1/m)^m]^6  (put m = n/3, when n à ∞ then, n à ∞) 

Limxà + ∞ (1 + 3/n)^2n = e^6 

You can take assistance from a limit solver to evaluate the limit value to get rid of manual calculations. 

Example 2: 

Evaluate Lim θà 0 sin 7θ/ θ 

Solution:  

Step 1: Given the data 

Lim θà 0 sin 7θ/ θ 

Step 2: Compare the required problem with the following result. 

Lim θà 0 sin θ/ θ = 1 

Step 3: Now 

Let x = 7θ so that θ = x/7 

When θ à 0, we have x à 0 

So,  

Limθà 0 sin 7θ/ θ = Lim xà 0 (sin x) /(x/7) = 7 Lim xà 0 sin x/ x 

Limθà 0 sin 7θ/ θ = 7 (1) = 7 Ans. 

Conclusion: 

In conclusion, the versatile nature of limits makes them a cornerstone of mathematical analysis. In this article, we have explored the concept of limits, its basic definition, significant types, some important deductions, and examples. Hopefully, by apprehending this article you will be able to tackle the problems related to limits.