# 9 Lecture

## Limits (Intuitive Introduction)

A limit is a value that a function approaches as the input variable gets closer to a certain value. The input variable is usually denoted by x, and the value it approaches is called the limit point.

## Important Mcq's Midterm & Finalterm Prepration Past papers included

1. What is the limit of f(x) as x approaches 3 for the function f(x) = x + 2? a) 3 b) 5 c) 6 d) None of the above

Solution: b) 5

1. What is the limit of f(x) as x approaches infinity for the function f(x) = 1/x? a) 0 b) 1 c) infinity d) None of the above

Solution: a) 0

1. What is the limit of f(x) as x approaches 2 for the function f(x) = (x-2)/(x+4)? a) 2 b) 0 c) 1 d) None of the above

Solution: b) 0

1. What is the limit of f(x) as x approaches -3 for the function f(x) = |x+3|? a) -3 b) 0 c) 3 d) None of the above

Solution: c) 3

1. What is the limit of f(x) as x approaches 0 for the function f(x) = sin(x)/x? a) 1 b) 0 c) -1 d) None of the above

Solution: a) 1

1. What is the limit of f(x) as x approaches 4 for the function f(x) = (x-4)/(x^2-16)? a) 1/12 b) 1/4 c) 1/8 d) None of the above

Solution: b) 1/4

1. What is the limit of f(x) as x approaches -infinity for the function f(x) = e^x? a) 0 b) -1 c) infinity d) None of the above

Solution: a) 0

1. What is the limit of f(x) as x approaches 1 for the function f(x) = (x-1)/(x^2-1)? a) -1/2 b) 1/2 c) 1 d) None of the above

Solution: b) 1/2

1. What is the limit of f(x) as x approaches 2 for the function f(x) = (x^2-4)/(x-2)? a) 2 b) 0 c) 4 d) None of the above

Solution: c) 4

1. What is the limit of f(x) as x approaches 0 for the function f(x) = (1-cos(x))/x^2? a) 0 b) 1/2 c) infinity d) None of the above

Solution: b) 1/2

## Subjective Short Notes Midterm & Finalterm Prepration Past papers included

1. What is a limit in calculus? A limit is a value that a function approaches as the input variable gets closer to a certain value.

2. What is the importance of limits in calculus? Limits are important because they can be used to calculate the behavior of a function as it approaches certain points.

3. What is the limit of a function f(x) as x approaches a? The limit of a function f(x) as x approaches a is the value that f(x) approaches as x gets arbitrarily close to a.

4. What is the formal definition of limits? The formal definition of limits involves the concept of epsilon-delta. It states that the limit of a function exists if and only if for any ? > 0, there exists a ? > 0 such that |f(x) - L| < ? whenever 0 < |x - a| < ?.

5. What is the concept of one-sided limits? One-sided limits are used when the limit from the left or the right of a value is different.

6. What is the difference between a limit and a function value? A function value is the value of the function at a specific point, while a limit is a value that the function approaches as the input variable gets arbitrarily close to a certain value.

7. What is the limit of a constant function? The limit of a constant function is the same as the value of the constant.

8. What is the limit of a rational function as x approaches infinity? The limit of a rational function as x approaches infinity depends on the degree of the numerator and denominator. If the degree of the numerator is less than the degree of the denominator, the limit is zero. If the degrees are equal, the limit is the ratio of the leading coefficients. If the degree of the numerator is greater than the degree of the denominator, the limit is either infinity or negative infinity depending on the signs of the leading coefficients.

9. What is the limit of a function that has a vertical asymptote? The limit of a function that has a vertical asymptote does not exist at the point of the vertical asymptote.

10. How can limits be used to calculate derivatives? Limits are used to calculate derivatives by taking the limit of the difference quotient as the change in x approaches zero.

### Limits (Intuitive Introduction)

Calculus is a branch of mathematics that deals with the study of continuous change. It has two main branches, differential calculus and integral calculus. Limits are one of the most important concepts in calculus, and they are used to define derivatives and integrals. In this article, we will provide an intuitive introduction to limits. What are Limits? A limit is a value that a function approaches as the input variable gets closer to a certain value. The input variable is usually denoted by x, and the value it approaches is called the limit point. Limits are important because they can be used to calculate the behavior of a function as it approaches certain points. To understand limits, let us consider a simple example. Consider the function f(x) = x^2 - 1. If we take values of x close to 2, such as 1.9, 1.99, and 1.999, we can see that f(x) gets closer and closer to 3. Therefore, we can say that the limit of f(x) as x approaches 2 is 3, denoted by the following equation: Lim(x?2) f(x) = 3 This means that as x gets arbitrarily close to 2, f(x) gets arbitrarily close to 3. One-Sided Limits So far, we have only discussed limits as x approaches a certain value. However, there are situations where the limit from the left or the right of a value is different. For example, consider the function g(x) = 1/x. If we approach x = 0 from the right, g(x) becomes very large and positive. If we approach x = 0 from the left, g(x) becomes very large and negative. Therefore, we cannot say that the limit of g(x) as x approaches 0 exists. Formal Definition of Limits The formal definition of limits involves the concept of epsilon-delta. Let us consider a function f(x) and a limit point a. We say that the limit of f(x) as x approaches a exists if and only if for any ? > 0, there exists a ? > 0 such that: |f(x) - L| < ? whenever 0 < |x - a| < ? where L is the limit of f(x) as x approaches a. This definition may seem complicated, but it simply means that we can get the function arbitrarily close to the limit by taking the input variable sufficiently close to the limit point. Limits at Infinity Sometimes, we want to know the behavior of a function as the input variable gets very large or very small. In such cases, we use the concept of limits at infinity. The limit of a function f(x) as x approaches infinity exists if and only if for any ? > 0, there exists an M such that: |f(x) - L| < ? whenever x > M where L is the limit of f(x) as x approaches infinity. Example of Limits at Infinity Consider the function h(x) = 1/x. As x gets larger and larger, h(x) gets closer and closer to zero. We can express this as follows: lim(x??) h(x) = 0 This means that as x gets arbitrarily large, h(x) gets arbitrarily close to zero. Conclusion Limits are an important concept in calculus that allow us to understand the behavior of functions as they approach certain values or as the input variable gets very large or small. The concept of limits is used to define derivatives and integrals, which are fundamental concepts in calculus. By understanding limits, we can gain a deeper understanding of calculus and its applications in various fields of science and engineering.