Physics Wallah

Differentiation: Formulas, Functions, Rules, and Examples

Differentiation is a fundamental concept in calculus, used to find the rate at which a function changes. Learn about its definition, rules, and formulas in detail.
authorImageShruti Dutta22 Dec, 2024
Share

Share

Differentiation

Differentiation is a fundamental concept in calculus that involves finding the rate at which a function changes as its input changes. In simpler terms, it is the process of calculating the derivative of a function.

The derivative of a function at a given point gives the slope of the tangent line to the curve at that point, representing how steep or flat the curve is. Differentiation measures the instantaneous rate of change of a function with respect to one of its variables. It is widely used in various fields, such as physics, economics, engineering, and biology, to analyze and model real-world phenomena involving motion, growth, optimization, and more. The process of differentiation relies on a set of rules and techniques, such as the sum rule, product rule, quotient rule, and chain rule, which help compute derivatives of different types of functions. [video width="1920" height="1080" mp4="https://www.pw.live/exams/wp-content/uploads/2024/12/Copy-of-Corurious-Jr-Reel-2-Landscape-1-2-1.mp4"][/video]

Differentiation Formula

Differentiation is the process of calculating the rate of change of a function with respect to its variable. The derivatives of various types of functions, such as algebraic, exponential, and trigonometric functions, are derived using basic principles and established formulas. Power Function Derivative : Consider a function 𝑦=π‘₯𝑛, where 𝑛>0. The difference between the function value at π‘₯+Ξ”π‘₯ andπ‘₯

𝑓(π‘₯+Ξ”π‘₯)βˆ’π‘“(π‘₯)=(π‘₯+Ξ”π‘₯)π‘›βˆ’π‘₯

Taking the limit as Ξ”π‘₯ approaches 0 :

Ξ”π‘₯β†’0(π‘₯+Ξ”π‘₯)π‘›βˆ’π‘₯𝑛Δπ‘₯=lim/ 𝑦→π‘₯π‘¦π‘›βˆ’π‘₯π‘›π‘¦βˆ’π‘₯=𝑛⋅π‘₯π‘›βˆ’1Ξ”xβ†’0lim

​ This formula gives us the derivative of the power function

𝑦=π‘₯𝑛 as 𝑦′=𝑛⋅π‘₯π‘›βˆ’

Function of Differentiation

The rules of differentiation provide a systematic approach to finding the derivatives of more complex functions. Once we understand how to differentiate basic functions like constants, powers, trigonometric, and exponential functions, we can use these rules to handle combinations of these functions. These rules simplify the process of differentiation, making it easier to compute the rate of change for a wide variety of functions. Below are the key differentiation rules that are essential for solving most differentiation problems.

Also Check: Odd Numbers

[video width="1920" height="1080" mp4="https://www.pw.live/exams/wp-content/uploads/2024/12/Curious-Jr-Ad.mp4"][/video]

1. Derivatives of Basic Functions

To start, we need to understand the derivatives of basic types of functions, often referred to as elementary functions. These include constant functions, power functions, logarithmic functions, exponential functions, and trigonometric functions.
  • Constant Functions : For a constant function, where the output is always the same (i.e., the value doesn’t change no matter what xxx is), the rate of change is zero. This is because there is no change in the value of the function. Thus, the derivative of a constant function is always zero.
  • Power Functions : When a function is a power of x, like xnx^nxn (where n is a constant), the derivative tells us how the function’s output changes concerning changes in x For power functions, the derivative brings down the exponent as a coefficient and reduces the exponent by 1. This tells us how fast the function is changing at any given point.
  • Logarithmic Functions : Logarithmic functions, such as the natural logarithm ln⁑(x)\ln(x)ln(x), measure how a number grows exponentially. The derivative of logarithmic functions gives insight into how the growth rate changes. For example, the derivative of ln⁑(x)\ln(x)ln(x) is 1x\frac{1}{x}x1​, meaning the rate of growth decreases as x increases.
  • Exponential Functions : Exponential functions, like axa^xax where aaa is a constant, grow at a rate proportional to their current value. The derivative of an exponential function involves the original function multiplied by the natural logarithm of the base. This shows that exponential growth is not just fast but also grows faster as the base of the exponent increases.

2. Trigonometric Functions

Trigonometric functions like sine, cosine, tangent, and others are used to model periodic behaviors like waves. The derivative of a trigonometric function describes how the function’s value changes as the input angle changes. For example, the derivative of sine is cosine, showing how the sine function’s rate of change is directly related to the cosine of the angle.

3. Inverse Trigonometric Functions

Inverse trigonometric functions (like arcsine, arccosine, etc.) are used when you want to find the angle that corresponds to a given value of a trigonometric function. The derivatives of inverse trigonometric functions are useful when solving problems involving angles and distances. For instance, the derivative of the arcsine function sinβ‘βˆ’1(x)\sin^{-1}(x)sinβˆ’1(x) involves a square root, which indicates how steeply the function rises or falls as xxx changes.

Also Check: Area of Rectangle

Differentiation Rules

Once we know how to differentiation basic functions, we can apply rules to differentiate more complex functions. These rules help us find the derivative of functions that are combinations of simpler functions.

1. Sum Rule

The sum rule states that if a function is the sum (or difference) of two functions, then the derivative of the sum (or difference) is simply the sum (or difference) of the derivatives of the individual functions. This is intuitive because if we’re adding or subtracting functions, their rates of change simply add or subtract.

2. Product Rule

The product rule is used when we are differentiating the product of two functions. It tells us that the derivative of a product is the first function times the derivative of the second function, plus the second function times the derivative of the first function. This accounts for how each part of the product contributes to the overall rate of change.

3. Quotient Rule

When we differentiation a quotient of two functions, the quotient rule comes into play. It tells us that the derivative of a quotient is the denominator times the derivative of the numerator, minus the numerator times the derivative of the denominator, all divided by the denominator squared. This is useful when dealing with fractions or ratios of functions.

4. Chain Rule

The chain rule is used when we have a composition of functions, meaning one function inside another. It tells us to take the derivative of the outer function and multiply it by the derivative of the inner function. This is essential when dealing with nested functions or functions with multiple variables.

5. Constant Rule

If a function is a constant multiplied by another function, the derivative is simply the constant times the derivative of the other function. This rule shows that constants don’t affect the rate of change of a function they just scale it.

Rules of Differentiation

Differentiation involves finding the rate of change of a function, and while basic functions have standard derivative formulas, more complex functions often require specific rules to compute their derivatives. The most common rules are outlined below [video width="1920" height="1080" mp4="https://www.pw.live/exams/wp-content/uploads/2024/12/Courios-jr-Video.mp4"][/video]

1. Continuity and Differentiability

Before delving into the differentiation rules, it’s important to understand the relationship between differentiability and continuity: Differentiability Implies Continuity: If a function 𝑓 is differentiable at a point

π‘₯0, then it is continuous at π‘₯0

This means that for the function to be differentiable at a particular point, it must also not have any abrupt jumps or breaks at that point. Differentiability on an Interval : A function is said to be differentiable over an interval [π‘Ž,𝑏] if it is differentiable at every point within that interval. Additionally, some properties of differentiability:
  • The sum, difference, product, and composition of differentiable functions are themselves differentiable, wherever they are defined.
  • The quotient of two differentiable functions is also differentiable, except where the denominator is zero. This is a restriction when using the quotient rule.
Now, let’s explore the specific differentiation rules in detail:

2. The Sum Rule

The Sum Rule states that if a function 𝑦 is the sum (or difference) of two functions 𝑒(π‘₯), u(x) and 𝑣(π‘₯), then the derivative of 𝑦 is simply the sum (or difference) of the derivatives of 𝑒(π‘₯) and 𝑣(π‘₯). Formula :

If 𝑦=𝑒(π‘₯)±𝑣(π‘₯),

y=u(x)Β±v(x),then the derivative ofΒ  𝑦 is:𝑑𝑦𝑑π‘₯=𝑑𝑒𝑑π‘₯±𝑑𝑣𝑑π‘₯ Explanation : This rule allows you to differentiate each part of the function separately and then combine the results. Example : If 𝑦=3π‘₯2+5π‘₯y=3x 2+5x, then to differentiate, we apply the sum rule: 𝑑𝑦𝑑π‘₯=𝑑𝑑π‘₯(3π‘₯2)+𝑑𝑑π‘₯(5π‘₯)=6π‘₯+5

3. The Product Rule

The product rule is used when we are differentiating the product of two functions. If 𝑦 is the product of two functions 𝑒(π‘₯) and𝑣(π‘₯), then the derivative of 𝑦 is found using the following formula: Formula :

If, 𝑦=𝑒(π‘₯)⋅𝑣(π‘₯),then the derivative of 𝑦 is: 𝑑𝑦𝑑π‘₯=𝑒(π‘₯)⋅𝑑𝑣𝑑π‘₯+𝑣(π‘₯)⋅𝑑𝑒𝑑π‘₯

Explanation : You differentiate each function individually, but you have to apply both functions to the derivative of the other. Example: If 𝑦=π‘₯2⋅𝑒π‘₯, then applying the product rule: 𝑑𝑦𝑑π‘₯=π‘₯2⋅𝑑𝑑π‘₯(𝑒π‘₯)+𝑒π‘₯⋅𝑑𝑑π‘₯(π‘₯2)=π‘₯2⋅𝑒π‘₯+𝑒π‘₯β‹… 4. The Quotient Rule The Quotient Rule is used when differentiating a ratio of two functions. If 𝑦 is the quotient of two functions 𝑒(π‘₯) and 𝑣(π‘₯), then the derivative of 𝑦 is given by: Formula : If, 𝑦=𝑒(π‘₯)𝑣(π‘₯),y= v(x)u(x), then the derivative of 𝑦 is: 𝑑𝑦 𝑑π‘₯=𝑣(π‘₯)⋅𝑑𝑒𝑑π‘₯βˆ’π‘’(π‘₯)⋅𝑑𝑣𝑑π‘₯𝑣(π‘₯)2 Explanation : The quotient rule is essentially a more complex version of the product rule, where you subtract the derivative of the numerator, multiplied by the denominator, from the derivative of the denominator, multiplied by the numerator, and then divide the result by the square of the denominator. Example : If 𝑦=π‘₯2sin(π‘₯)y= sin(x)x 2, applying the quotient rule:𝑑𝑦𝑑π‘₯=sin(π‘₯)⋅𝑑𝑑π‘₯(π‘₯2)βˆ’π‘₯2⋅𝑑𝑑π‘₯(sin(π‘₯)sin2(π‘₯)=sin(π‘₯)β‹…2π‘₯βˆ’π‘₯2β‹…cos(π‘₯)sin2(π‘₯) 5. The Chain Rule The Chain Rule is essential when dealing with composite functions. It allows us to differentiate functions that are composed of other functions. If 𝑦 isΒ  function of 𝑒, x, the chain rule provides a method for differentiating 𝑦 y with respect to π‘₯. Formula :

If𝑦=𝑓(𝑒(π‘₯))

where 𝑒=𝑔(π‘₯), then the derivative of 𝑦 with respect to π‘₯𝑑𝑦𝑑π‘₯=𝑓′(𝑒)⋅𝑔′(π‘₯). Explanation : The chain rule says that to differentiate a composite function, you differentiate the outer function (evaluated at the inner function) and then multiply by the derivative of the inner function. Example: If 𝑦=sin(π‘₯2) , we treat the inside function as 𝑒 =π‘₯2 and apply the chain rule: 𝑑𝑦𝑑π‘₯=cos(π‘₯2)β‹…2π‘₯

Also Check: AM and PM

6. The Constant Rule

The Constant Rule is one of the simplest differentiation rules. It states that the derivative of a constant multiplied by a function is just the constant times the derivative of the function. Formula : If 𝑦=π‘˜β‹…π‘“(π‘₯), where π‘˜ s a constant, then the derivative of 𝑦is:𝑑𝑦𝑑π‘₯=π‘˜β‹…π‘‘π‘‘π‘₯𝑓(π‘₯) Explanation : The constant π‘˜ des not change, so it can simply be factored out when differentiating. Example: If , 𝑦=3π‘₯3 pplying the constant rule:𝑑𝑦𝑑π‘₯=3⋅𝑑𝑑π‘₯(π‘₯3)=3β‹…
Related Articles
Subtraction Sums Word Problems
What is an Abacus? Math Puzzles
Multiplication Worksheets : Multiplication Sums

Differentiation FAQs

What does a derivative represent?

A derivative represents the rate of change or slope of a function at a particular point. For example, if the function represents the position of an object over time, the derivative gives the object's velocity (the rate of change of position with respect to time).

What is the derivative of a constant?

The derivative of a constant function (like y=5y = 5y=5) is always zero because constants do not change, and therefore have no rate of change.

What is the difference between continuity and differentiability?

Continuity means that a function has no breaks or jumps, while differentiability means that a function has a well-defined tangent at every point in its domain.
Join 15 Million students on the app today!
Point IconLive & recorded classes available at ease
Point IconDashboard for progress tracking
Point IconMillions of practice questions at your fingertips
Download ButtonDownload Button
Banner Image
Banner Image
Free Learning Resources
Know about Physics Wallah
Physics Wallah is an Indian edtech platform that provides accessible & comprehensive learning experiences to students from Class 6th to postgraduate level. We also provide extensive NCERT solutions, sample paper, NEET, JEE Mains, BITSAT previous year papers & more such resources to students. Physics Wallah also caters to over 3.5 million registered students and over 78 lakh+ Youtube subscribers with 4.8 rating on its app.
We Stand Out because
We provide students with intensive courses with India’s qualified & experienced faculties & mentors. PW strives to make the learning experience comprehensive and accessible for students of all sections of society. We believe in empowering every single student who couldn't dream of a good career in engineering and medical field earlier.
Our Key Focus Areas
Physics Wallah's main focus is to make the learning experience as economical as possible for all students. With our affordable courses like Lakshya, Udaan and Arjuna and many others, we have been able to provide a platform for lakhs of aspirants. From providing Chemistry, Maths, Physics formula to giving e-books of eminent authors like RD Sharma, RS Aggarwal and Lakhmir Singh, PW focuses on every single student's need for preparation.
What Makes Us Different
Physics Wallah strives to develop a comprehensive pedagogical structure for students, where they get a state-of-the-art learning experience with study material and resources. Apart from catering students preparing for JEE Mains and NEET, PW also provides study material for each state board like Uttar Pradesh, Bihar, and others

Copyright Β© 2025 Physicswallah Limited All rights reserved.