# NCERT Solution Class 11 Chapter 13- Limits and Derivatives

The NCERT Solutions For Class 11 Maths Chapter 13 Limits and Derivatives are arranged topic wise in a systematic manner. The NCERT Solutions are authored by the most experienced educators in the teaching industry, writing the solutions for every problem in a simpler way. These solutions pdf comes handy for a Class 11 student to understand the idea of Limits and Derivatives.

## Download PDF of NCERT Solutions for Class 11 Maths Chapter 13- Limits and Derivatives

Exercise 13.1 Solutions 32 Questions

Exercise 13.2 Solutions 11 Questions

Miscellaneous Exercise On Chapter 13 Solutions 30 Questions

### Access Answers of Maths NCERT Class 11 Chapter 13

Exercise 13.1 page no: 301

1. Evaluate the Given limit:

Solution:

Given

Substituting x = 3, we get

= 3 + 3

= 6

2. Evaluate the Given limit:

Solution:

Given limit:

Substituting x = π, we get

= (π – 22 / 7)

3. Evaluate the Given limit:

Solution:

Given limit:

Substituting r = 1, we get

= π(1)2

= π

4. Evaluate the Given limit:

Solution:

Given limit:

Substituting x = 4, we get

= [4(4) + 3] / (4 – 2)

= (16 + 3) / 2

= 19 / 2

5. Evaluate the Given limit:

Solution:

Given limit:

Substituting x = -1, we get

= [(-1)10 + (-1)5 + 1] / (-1 – 1)

= (1 – 1 + 1) / – 2

= – 1 / 2

6. Evaluate the Given limit:

Solution:

Given limit:

= [(0 + 1)5 – 1] / 0

=0

Since, this limit is undefined

Substitute x + 1 = y, then x = y – 1

7. Evaluate the Given limit:

Solution:

8. Evaluate the Given limit:

Solution:

9. Evaluate the Given limit:

Solution:

= [a (0) + b] / c (0) + 1

= b / 1

= b

10. Evaluate the Given limit:

Solution:

11. Evaluate the Given limit:

Solution:

Given limit:

Substituting x = 1

= [a (1)2 + b (1) + c] / [c (1)2 + b (1) + a]

= (a + b + c) / (a + b + c)

Given

= 1

12. Evaluate the Given limit:

Solution:

By substituting x = – 2, we get

13. Evaluate the Given limit:

Solution:

Given

14. Evaluate the given limit:

Solution:

15. Evaluate the given limit:

Solution:

16. Evaluate the given limit:

Solution:

17. Evaluate the given limit:

Solution:

18. Evaluate the given limit:

Solution:

19. Evaluate the given limit:

Solution:

20. Evaluate the given limit:

Solution:

21. Evaluate the given limit:

Solution:

22. Evaluate the given limit:

Solution:

23.

Solution:

24. Find
, where

Solution:

25. Evaluate
, where f(x) =

Solution:

26. Find
, where f (x) =

Solution:

27. Find
, where

Solution:

28. Suppose
and if
what are possible values of a and b

Solution:

29. Let a1, a2,………an be fixed real numbers and define a function

f (x) = (x – a1) (x – a2) ……. (x – an).

What is
For some a ≠ a1, a2, ……. an, compute

Solution:

30. If  For what value (s) of a does exists?

Solution:

31. If the function f(x) satisfies , evaluate

Solution:

32. If  For what integers m and n does both and exist?

Solution:

Exercise 13.2 page no: 312

1. Find the derivative of x2– 2 at x = 10

Solution:

Let f (x) = x2 – 2

From first principle

2. Find the derivative of x at x = 1.

Solution:

Let f (x) = x

Then,

3. Find the derivative of 99x at x = l00.

Solution:

Let f (x) = 99x,

From first principle

= 99

4. Find the derivative of the following functions from first principle

(i) x3 – 27

(ii) (x – 1) (x – 2)

(iii) 1 / x2

(iv) x + 1 / x – 1

Solution:

(i) Let f (x) = x3 – 27

From first principle

(ii) Let f (x) = (x – 1) (x – 2)

From first principle

(iii) Let f (x) = 1 / x2

From first principle, we get

(iv) Let f (x) = x + 1 / x – 1

From first principle, we get

5. For the function  .Prove that f’ (1) =100 f’ (0).

Solution:

6. Find the derivative of  for some fixed real number a.

Solution:

7. For some constants a and b, find the derivative of
(i) (x − a) (x − b)

(ii) (ax2 + b)2

(iii) x – a / x – b

Solution:

(i) (x – a) (x – b)

(ii) (ax2 + b)2

= 4ax(ax2 + b)

(iii) x – a / x – b

8. Find the derivative of  for some constant a.

Solution:

9. Find the derivative of

(i) 2x – 3 / 4

(ii) (5x3 + 3x – 1) (x – 1)

(iii) x-3 (5 + 3x)

(iv) x5 (3 – 6x-9)

(v) x-4 (3 – 4x-5)

(vi) (2 / x + 1) – x2 / 3x – 1

Solution:

(i)

(ii)

(iii)

(iv)

(v)

(vi)

10. Find the derivative of cos x from first principle

Solution:

11. Find the derivative of the following functions:

(i) sin x cos x

(ii) sec x

(iii) 5 sec x + 4 cos x

(iv) cosec x

(v) 3 cot x + 5 cosec x

(vi) 5 sin x – 6 cos x + 7

(vii) 2 tan x – 7 sec x

Solution:

(i) sin x cos x

(ii) sec x

(iii) 5 sec x + 4 cos x

(iv) cosec x

(v) 3 cot x + 5 cosec x

(vi)5 sin x – 6 cos x + 7

(vii) 2 tan x – 7 sec x

Miscellaneous exercise page no: 317

1. Find the derivative of the following functions from first principle:

(i) –x

(ii) (–x)–1

(iii) sin (x + 1)

(iv)

Solution:

(ii) (-x)-1

= 1 / x2

(iii) sin (x + 1)

(iv)

We get,

Find the derivative of the following functions (it is to be understood that abcdp, q, r and s are fixed non-zero constants and m and n are integers):

2. (x + a)

Solution:

3. (px + q) (r / x + s)

Solution:

4. (ax + b) (cx d)2

Solution:

5. (ax + b) / (cx + d)

Solution:

6. (1 + 1 / x) / (1 – 1 / x)

Solution:

7. 1 / (ax2 + bx + c)

Solution:

8. (ax + b) / px2 + qx + r

Solution:

9. (px2 + qx + r) / ax + b

Solution:

10. (a / x4) – (b / x2) + cox x

Solution:

11.

Solution:

12. (ax + b)n

Solution:

13. (ax + b)n (cx + d)m

Solution:

14. sin (x + a)

Solution:

15. cosec x cot x

Solution:

So, we get

16.

Solution:

17.

Solution:

18.

Solution:

19. sinn x

Solution:

20.

Solution:

21.

Solution:

22. x4 (5 sin x – 3 cos x)

Solution:

23. (x2 + 1) cos x

Solution:

24. (ax2 + sin x) (p + q cos x)

Solution:

25.

Solution:

26.

Solution:

27.

Solution:

28.

Solution:

29. (x + sec x) (x – tan x)

Solution:

30.

Solution:

 Also Access NCERT Exemplar for Class 11 Maths Chapter 13 CBSE Notes for Class 11 Maths Chapter 13

## NCERT Solutions for Class 11 Maths Chapter 13- Limits and Derivatives

Class 11 Maths Chapter 13 Limits and Derivatives of NCERT Solutions include the following:

13.1 Introduction

This section introduces the branch of mathematics called calculus, derivative, limits and algebra of limits. Derivatives of certain standard functions are also discussed.

• Calculus is used in electrical engineering to find the length of wire to be used between two stations which are miles apart.
• Calculus is used to find the velocity and trajectory of an object.
• Calculus is used in operations research to improve efficiency, productivity and earn profits.

13.2 Intuitive Idea of Derivatives

This section defines the derivative of a function by giving a real-life example of distance travelled at different intervals of time.

The derivative is the rate of change at which one quantity varies concerning another. If you run a business (say selling candies), derivatives can help you decide what quantity you should sell. The data of your business performance over the past few months is to be taken and the trend needs to be analyzed by plotting a curve. Derivative defines the instantaneous slope (dy/dx) of this graph.

The slope gives an idea of the marginal cost (change in cost/change in unit produced) of producing every additional unit at that instant. If this cost is greater than 10 bucks that is the selling price, then a loss is incurred at the point.

For better clarity, refer to the table given below.

For 0-300 units, if the cost > sales, then it’s a loss

For 400-600 units, if the sales > cost, then it’s a profit

13.3 Limits

This section explains limits with an interesting example, left-hand limit and right-hand limit with solved problems.

If an ice cube is dropped into a glass of warm water and the temperature is measured with time, it is an example of limit as the time approaches infinity. The time measured here is the temperature slowly attaining the room temperature where the glass was stored.

13.3.1 Algebra of limits

This section demonstrates the output of sum, difference, product and quotient of limits.

13.3.2 Limits of polynomials and rational functions

The limits of polynomials and rational functions are elaborated along with solved examples.

13.4 Limits of Trigonometric Functions

This section deals with the theorems and prepositions for functions, which are helpful in calculating the limits of some trigonometric functions.

13.5 Derivatives

This section helps the student to find solutions on different derivative problems.

Money related establishments need to anticipate the adjustments in the estimation of a specific stock knowing its present worth. In this, and numerous such cases, it is important to know how a specific parameter is changing in accordance with the other parameter. The heart of the text is derivative of a function at a given point in its domain of definition.

13.5.1 Algebra of derivatives of functions

This section demonstrates the output of sum, difference, product and quotient of derivatives.

13.5.2 Derivative of polynomials and trigonometric functions

This section deals with the theorems and problems for functions which help calculate the derivatives of some trigonometric functions.

## A few points on Chapter 13 Limits and Derivatives

• The expected value of the function, as dictated by the points to the left of a point defines the left-hand limit of the function at that point. Similarly the right-hand limit.
• Limit of a function at a point is the common value of the left and right-hand limits if they coincide.
• For a function f and a real number, a lim x → a f(x) and f (a) may not be the same.

The solutions given in the pdf contain a definite clarification for each problem. The NCERT Solutions for Class 11 Maths Chapter 13 Limits and Derivatives are accessible on your fingertips!! The solutions are set up so that a student will have a comprehension of the split-up marks for every part, which thus benefits them to identify the time and energy they need to allocate to every section. High scoring students have suggested NCERT solutions to get sound information on each topic.