Arithmetic Progression
Arithmetic Progression
Arithmetic Progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is constant. This constant difference is called the common difference (d).
The general formula for the nth term of an AP is: Tn = a + (n1)d where a is the first term, n is the number of the term, and d is the common difference.
For example, if the first term (a) is 5 and the common difference (d) is 3, then the 10th term (T10) of the AP is: T10 = 5 + (101)3 = 5 + 9*3 = 32
The sum of the first n terms of an AP is given by the formula: Sn = n/2(2a + (n1)d) where a is the first term, n is the number of terms, and d is the common difference.
APs have various applications in mathematics and reallife scenarios, such as calculating the sum of a series of numbers, modeling linear growth, and solving problems involving consecutive integers.
What is Arithmetic Progression?
Arithmetic Progression (AP)
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is the same. This common difference is often denoted by ’d'.
The general formula for the nth term of an AP is:
T_n = a + (n1)d
where:
 T_n is the nth term of the AP
 a is the first term of the AP
 d is the common difference
 n is the number of the term
Example:
Consider the following sequence of numbers:
2, 5, 8, 11, 14, ...
This sequence is an AP with a common difference of 3. The first term is 2, and the second term is 5. The difference between these two terms is 3. The third term is 8, and the difference between the second and third terms is also 3. This pattern continues for all the terms in the sequence.
Properties of AP:
 The sum of the first n terms of an AP is given by the formula:
S_n = n/2(a + T_n)
where:

S_n is the sum of the first n terms of the AP

a is the first term of the AP

T_n is the nth term of the AP

n is the number of terms

The arithmetic mean of an AP is given by the formula:
A = (a + T_n)/2
where:
 A is the arithmetic mean of the AP
 a is the first term of the AP
 T_n is the nth term of the AP
Applications of AP:
APs have a wide range of applications in various fields, including mathematics, physics, engineering, and economics. Some examples of applications of APs include:
 In mathematics, APs are used to study sequences and series.
 In physics, APs are used to study motion with constant acceleration.
 In engineering, APs are used to design and analyze structures.
 In economics, APs are used to study population growth and economic growth.
Notation in Arithmetic Progression
Notation in Arithmetic Progression
In arithmetic progression (AP), we use specific notation to represent the terms and other important elements of the progression. Here’s an explanation of the commonly used notations:
1. First Term (a):
 The first term of an AP is denoted by ‘a’.
 It represents the initial value from which the progression starts.
2. Common Difference (d):
 The common difference of an AP is denoted by ’d'.
 It represents the constant value added to each term to obtain the next term.
3. nth Term (a_n):
 The nth term of an AP is denoted by ‘a_n’.
 It represents the value of the term at the nth position in the progression.
4. General Term Formula:
 The general term formula for an AP is given by: a_n = a + (n  1)d
 This formula helps us find the value of any term in the progression based on its position (n).
5. Sum of n Terms (S_n):
 The sum of the first n terms of an AP is denoted by ‘S_n’.
 It represents the total value obtained by adding all the terms from the first term (a) to the nth term (a_n).
6. Sum of n Terms Formula:
 The sum of n terms formula for an AP is given by: S_n = n/2 * (a + a_n)
 This formula helps us find the total sum of the first n terms in the progression.
Examples:
1. Arithmetic Progression:
 Consider an AP with a = 5 and d = 3.
 The first few terms of this AP are: 5, 8, 11, 14, 17, …
2. Finding the nth Term:
 To find the 10th term (a_10) of the AP with a = 5 and d = 3, we use the formula: a_n = a + (n  1)d a_10 = 5 + (10  1)3 a_10 = 5 + 9 * 3 a_10 = 5 + 27 a_10 = 32
 Therefore, the 10th term of the AP is 32.
3. Finding the Sum of n Terms:
 To find the sum of the first 10 terms (S_10) of the AP with a = 5 and d = 3, we use the formula: S_n = n/2 * (a + a_n) S_10 = 10/2 * (5 + 32) S_10 = 5 * 37 S_10 = 185
 Therefore, the sum of the first 10 terms of the AP is 185.
In summary, the notation used in arithmetic progression helps us represent and manipulate the terms, common difference, nth term, and sum of terms in a clear and concise manner.
General Form of an AP
General Form of an Arithmetic Progression (AP)
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive terms is the same. This constant difference is called the common difference of the AP.
The general form of an AP is:
a, a + d, a + 2d, a + 3d, ..., a + nd
where:
 a is the first term of the AP.
 d is the common difference of the AP.
 n is the number of terms in the AP.
For example, consider the AP 3, 7, 11, 15, 19, …. Here, the first term (a) is 3, and the common difference (d) is 4. So, the general form of this AP is:
3, 3 + 4, 3 + 2(4), 3 + 3(4), 3 + 4(4), ...
Simplifying this expression, we get:
3, 7, 11, 15, 19, ...
which is the given AP.
Properties of an AP
 The sum of the first n terms of an AP is given by the formula:
Sn = n/2(2a + (n  1)d)
where:

Sn is the sum of the first n terms of the AP.

a is the first term of the AP.

d is the common difference of the AP.

n is the number of terms in the AP.

The nth term of an AP is given by the formula:
Tn = a + (n  1)d
where:
 Tn is the nth term of the AP.
 a is the first term of the AP.
 d is the common difference of the AP.
 n is the number of the term in the AP.
Examples of APs
 The sequence 1, 3, 5, 7, 9, … is an AP with a = 1 and d = 2.
 The sequence 2, 4, 6, 8, 10, … is an AP with a = 2 and d = 2.
 The sequence 3, 6, 9, 12, 15, … is an AP with a = 3 and d = 3.
Applications of APs
APs are used in a variety of applications, including:
 Finding the sum of a series of numbers.
 Calculating the average of a set of numbers.
 Modeling realworld phenomena, such as population growth and radioactive decay.
Arithmetic Progression Formulas
Arithmetic Progression Formulas
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is the same. The first term of an AP is denoted by a, and the common difference is denoted by d. The nth term of an AP is given by the formula:
$$T_n = a + (n1)d$$
where:
 Tn is the nth term of the AP
 a is the first term of the AP
 d is the common difference
 n is the number of terms in the AP
Example:
Consider the AP 2, 5, 8, 11, 14, ….
Here, the first term (a) is 2, and the common difference (d) is 3. The 10th term of this AP can be calculated as follows:
$$T_{10} = 2 + (101)3 = 2 + 9 \times 3 = 29$$
Sum of an Arithmetic Progression
The sum of the first n terms of an AP is given by the formula:
$$S_n = \frac{n}{2}[2a + (n1)d]$$
where:
 Sn is the sum of the first n terms of the AP
 a is the first term of the AP
 d is the common difference
 n is the number of terms in the AP
Example:
Consider the AP 2, 5, 8, 11, 14, ….
The sum of the first 10 terms of this AP can be calculated as follows:
$$S_{10} = \frac{10}{2}[2 \times 2 + (101)3] = 5 \times [4 + 9 \times 3] = 5 \times 31 = 155$$
Applications of Arithmetic Progression Formulas
Arithmetic progression formulas have a wide range of applications in various fields, including mathematics, physics, engineering, and finance. Some examples of applications include:
 Calculating the sum of a series of numbers
 Finding the nth term of a sequence
 Modeling the growth of a population
 Calculating the velocity and acceleration of an object in motion
 Determining the present value or future value of an investment
Conclusion
Arithmetic progression formulas are powerful tools that can be used to solve a variety of problems. By understanding these formulas and their applications, you can gain a deeper understanding of the world around you.
nth Term of an AP
The nth term of an arithmetic progression (AP) is a formula that gives the value of the nth term of the progression. It is based on the concept of common difference, which is the difference between any two consecutive terms of the progression.
Formula for the nth term of an AP:
The formula for the nth term of an AP is given by:
T(n) = a + (n  1) * d
where:
 T(n) is the nth term of the AP
 a is the first term of the AP
 n is the number of the term we want to find
 d is the common difference of the AP
Example:
Let’s consider an AP with a first term of 5 and a common difference of 3. We want to find the 10th term of this AP.
Using the formula, we have:
T(10) = 5 + (10  1) * 3
T(10) = 5 + 9 * 3
T(10) = 5 + 27
T(10) = 32
Therefore, the 10th term of the AP is 32.
Properties of the nth term of an AP:
 The nth term of an AP is a linear function of n.
 The graph of the nth term of an AP is a straight line.
 The slope of the graph of the nth term of an AP is equal to the common difference of the AP.
Applications of the nth term of an AP:
 The nth term of an AP can be used to find the sum of n terms of an AP.
 The nth term of an AP can be used to find the missing terms of an AP.
 The nth term of an AP can be used to generate an AP.
Types of AP
Types of Access Points (APs)
Access points (APs) are devices that connect wireless devices to a wired network. They act as a bridge between the wireless and wired worlds, allowing devices to communicate with each other and access the internet. There are several types of APs, each with its own unique features and capabilities.
1. Standalone APs:
Standalone APs are individual devices that can be plugged into an electrical outlet and connected to a wired network. They are typically used in small businesses, homes, and public spaces to provide wireless coverage. Standalone APs are relatively easy to set up and manage, and they can be configured to support a variety of wireless standards, including 802.11a/b/g/n/ac.
2. Enterprise APs:
Enterprise APs are designed for use in large businesses and organizations. They offer more advanced features and capabilities than standalone APs, such as centralized management, load balancing, and security features. Enterprise APs are typically managed by a network controller, which allows administrators to configure and monitor the APs from a central location.
3. Outdoor APs:
Outdoor APs are designed to be used in outdoor environments, such as parks, stadiums, and campuses. They are typically more rugged and weatherresistant than indoor APs, and they can be equipped with features such as longrange antennas and PoE (Power over Ethernet) support.
4. Mesh APs:
Mesh APs are a type of wireless network that uses multiple APs to create a selfhealing, selforganizing network. Mesh APs are often used in areas where it is difficult or impossible to run wired cables, such as rural areas or construction sites.
5. PoE APs:
PoE (Power over Ethernet) APs are devices that can be powered over an Ethernet cable. This eliminates the need for a separate power outlet, making PoE APs ideal for use in areas where there is limited access to power outlets.
6. Dualband APs:
Dualband APs support two different frequency bands, typically 2.4 GHz and 5 GHz. This allows devices to connect to the AP on the band that provides the best performance. Dualband APs are ideal for use in environments where there is a lot of wireless traffic, as they can help to reduce congestion.
7. Triband APs:
Triband APs support three different frequency bands, typically 2.4 GHz, 5 GHz, and 6 GHz. This provides even more flexibility for devices to connect to the AP on the band that provides the best performance. Triband APs are ideal for use in environments where there is a very high demand for wireless bandwidth.
8. Cloudmanaged APs:
Cloudmanaged APs are devices that are managed from a cloudbased platform. This allows administrators to configure and monitor the APs from anywhere in the world. Cloudmanaged APs are ideal for use in businesses that have multiple locations or that want to centralize their network management.
9. Softwaredefined APs:
Softwaredefined APs (SDAPs) are devices that are controlled by software rather than hardware. This allows administrators to customize the APs to meet the specific needs of their network. SDAPs are ideal for use in businesses that want to have more control over their network infrastructure.
10. Virtual APs:
Virtual APs (VAPs) are logical APs that are created on a single physical AP. This allows administrators to create multiple wireless networks with different SSIDs, security settings, and traffic policies. VAPs are ideal for use in businesses that want to provide different levels of access to different users.
Examples of APs:
 Standalone APs: Ubiquiti UniFi AP AC Lite, TPLink Archer C7, Netgear Nighthawk AC1900
 Enterprise APs: Cisco Aironet 2800 Series, Aruba Instant On AP11D, Ruckus R510
 Outdoor APs: Ubiquiti UniFi AP Outdoor+, TPLink EAP225Outdoor, EnGenius EWS357AP
 Mesh APs: Ubiquiti AmpliFi HD Mesh System, TPLink Deco M5, Netgear Orbi RBK50
 PoE APs: Ubiquiti UniFi AP AC Pro, TPLink EAP245, Netgear Nighthawk AC1750
 Dualband APs: Ubiquiti UniFi AP AC Lite, TPLink Archer C7, Netgear Nighthawk AC1900
 Triband APs: Ubiquiti UniFi AP AC Pro, TPLink Archer C5400, Netgear Nighthawk X10
 Cloudmanaged APs: Ubiquiti UniFi Cloud Key, TPLink Omada Cloud Controller, Netgear Insight Instant Cloud Managed AP
 Softwaredefined APs: OpenWrt, DDWRT, Tomato
 Virtual APs: Ubiquiti UniFi AP AC Pro, TPLink Archer C7, Netgear Nighthawk AC1900
Sum of N Terms of AP
The sum of N terms of an arithmetic progression (AP) is a fundamental concept in mathematics, particularly in the study of sequences and series. An arithmetic progression is a sequence of numbers in which the difference between any two consecutive terms is constant. This constant difference is known as the common difference (d).
The formula for the sum of N terms of an AP is given by:
S_N = N/2 * (2a + (N  1) * d)
where:
 S_N represents the sum of the first N terms of the AP.
 a is the first term of the AP.
 d is the common difference of the AP.
 N is the number of terms to be summed.
To understand this formula better, let’s consider an example. Suppose we have an AP with a first term (a) of 5 and a common difference (d) of 3. We want to find the sum of the first 10 terms (N = 10) of this AP.
Plugging these values into the formula, we get:
S_10 = 10/2 * (2 * 5 + (10  1) * 3)
Simplifying the expression:
S_10 = 5 * (10 + 9 * 3)
S_10 = 5 * (10 + 27)
S_10 = 5 * 37
S_10 = 185
Therefore, the sum of the first 10 terms of the AP with a first term of 5 and a common difference of 3 is 185.
This formula can be used to find the sum of N terms of any AP, given the first term (a) and the common difference (d). It is a useful tool in various mathematical applications, including calculating the total distance traveled by an object moving with constant acceleration, finding the sum of a series of payments or deposits, and many more.
List of Arithmetic Progression Formulas
Arithmetic Progression (AP) Formulas:
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive terms is the same. This constant difference is called the common difference (d).
Here are some important formulas related to arithmetic progressions:
1. nth Term of an AP:
The nth term of an AP is given by the formula:
$$T_n = a + (n1)d$$
where:
 $$T_n$$ is the nth term of the AP.
 $$a$$ is the first term of the AP.
 $$n$$ is the number of the term we want to find.
 $$d$$ is the common difference of the AP.
Example:
If the first term of an AP is 5 and the common difference is 3, then the 10th term of the AP is:
$$T_{10} = 5 + (101)3 = 5 + 9(3) = 32$$
2. Sum of n Terms of an AP:
The sum of the first n terms of an AP is given by the formula:
$$S_n = \frac{n}{2}[2a + (n1)d]$$
where:
 $$S_n$$ is the sum of the first n terms of the AP.
 $$a$$ is the first term of the AP.
 $$n$$ is the number of terms we want to sum.
 $$d$$ is the common difference of the AP.
Example:
If the first term of an AP is 10 and the common difference is 5, then the sum of the first 10 terms of the AP is:
$$S_{10} = \frac{10}{2}[2(10) + (101)5] = 5[20 + 45] = 5(65) = 325$$
3. nth Term from the End of an AP:
The nth term from the end of an AP is given by the formula:
$$T_n = a + (n1)(d)$$
where:
 $$T_n$$ is the nth term from the end of the AP.
 $$a$$ is the first term of the AP.
 $$n$$ is the number of the term we want to find from the end.
 $$d$$ is the common difference of the AP.
Example:
If the first term of an AP is 15 and the common difference is 4, then the 5th term from the end of the AP is:
$$T_5 = 15 + (51)(4) = 15 + 4(4) = 15  16 = 1$$
4. Sum of n Terms from the End of an AP:
The sum of the last n terms of an AP is given by the formula:
$$S_n = \frac{n}{2}[2a + (n1)(d)]$$
where:
 $$S_n$$ is the sum of the last n terms of the AP.
 $$a$$ is the first term of the AP.
 $$n$$ is the number of terms we want to sum from the end.
 $$d$$ is the common difference of the AP.
Example:
If the first term of an AP is 20 and the common difference is 3, then the sum of the last 5 terms of the AP is:
$$S_5 = \frac{5}{2}[2(20) + (51)(3)] = \frac{5}{2}[40 + 4(3)] = \frac{5}{2}[40  12] = \frac{5}{2}(28) = 70$$
These formulas are useful for solving various problems involving arithmetic progressions.
Arithmetic Progressions Solved Examples
Arithmetic Progressions Solved Examples
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is the same. The first term of an AP is called the first term, and the common difference between any two consecutive terms is called the common difference.
Example 1:
Find the first four terms of an AP with first term 5 and common difference 3.
Solution:
The first term of the AP is 5. The second term is 5 + 3 = 8. The third term is 8 + 3 = 11. The fourth term is 11 + 3 = 14.
Therefore, the first four terms of the AP are 5, 8, 11, and 14.
Example 2:
Find the sum of the first 10 terms of an AP with first term 7 and common difference 2.
Solution:
The formula for the sum of the first n terms of an AP is:
$$S_n = \frac{n}{2}(2a + (n  1)d)$$
where:
 S_{n} is the sum of the first n terms
 a is the first term
 d is the common difference
 n is the number of terms
In this case, a = 7, d = 2, and n = 10. Substituting these values into the formula, we get:
$$S_{10} = \frac{10}{2}(2(7) + (10  1)2)$$ $$S_{10} = 5(14 + 9(2))$$ $$S_{10} = 5(32)$$ $$S_{10} = 160$$
Therefore, the sum of the first 10 terms of the AP is 160.
Example 3:
Find the 15th term of an AP with first term 4 and common difference 5.
Solution:
The formula for the nth term of an AP is:
$$T_n = a + (n  1)d$$
where:
 T_{n} is the nth term
 a is the first term
 d is the common difference
 n is the number of the term
In this case, a = 4, d = 5, and n = 15. Substituting these values into the formula, we get:
$$T_{15} = 4 + (15  1)5$$ $$T_{15} = 4 + 14(5)$$ $$T_{15} = 4 + 70$$ $$T_{15} = 74$$
Therefore, the 15th term of the AP is 74.
Practice Problems on AP
Practice Problems on AP
AP exams are rigorous and challenging, and it’s important to be wellprepared in order to succeed. One of the best ways to prepare is to practice with AP practice problems. These problems can help you identify your strengths and weaknesses, and they can also help you get used to the format of the AP exam.
There are many different resources available for AP practice problems. You can find practice problems in textbooks, online, and from your AP teacher. Some popular resources for AP practice problems include:
 The College Board’s AP Practice Exams
 Barron’s AP Review Books
 Princeton Review AP Review Books
 Kaplan AP Review Books
 McGrawHill AP Review Books
When you’re practicing with AP practice problems, it’s important to simulate the testing environment as much as possible. This means working in a quiet place, setting a time limit for yourself, and not using any outside resources. It’s also important to review your answers carefully after you’ve completed the practice test. This will help you identify the areas where you need more practice.
Here are some examples of AP practice problems:
AP English Language and Composition
 Read the following passage and then answer the questions that follow.
The Declaration of Independence is one of the most important documents in American history. It is the founding document of the United States of America, and it sets forth the principles of freedom, equality, and democracy that the country was founded on. The Declaration of Independence was written by Thomas Jefferson in 1776, and it was signed by the Continental Congress on July 4, 1776.
 What is the main idea of the passage?
 What are the three principles that the Declaration of Independence sets forth?
 Who wrote the Declaration of Independence?
 When was the Declaration of Independence signed?
AP Calculus AB
 Find the derivative of the following function.
$$f(x) = x^3 + 2x^2  3x + 4$$
 Find the indefinite integral of the following function.
$$f(x) = x^2 + 3x  2$$
 Find the area under the curve of the following function between x = 0 and x = 2.
$$f(x) = x^2  4x + 3$$
AP Physics 1
 A 10kg object is moving at a velocity of 20 m/s. What is the object’s kinetic energy?
$$KE = \frac{1}{2}mv^2$$
$$KE = \frac{1}{2}(10 kg)(20 m/s)^2$$
$$KE = 2000 J$$
 A 20kg object is lifted to a height of 10 meters. What is the object’s potential energy?
$$PE = mgh$$
$$PE = (20 kg)(9.8 m/s^2)(10 m)$$
$$PE = 1960 J$$
 A 30kg object is moving at a velocity of 15 m/s. The object collides with a 40kg object that is at rest. What is the velocity of the two objects after the collision?
$$m_1v_1 + m_2v_2 = (m_1 + m_2)v_f$$
$$(30 kg)(15 m/s) + (40 kg)(0 m/s) = (30 kg + 40 kg)v_f$$
$$450 kg m/s = 70 kg v_f$$
$$v_f = 6.43 m/s$$
These are just a few examples of AP practice problems. There are many more resources available, so be sure to do your research and find the practice problems that are right for you.
Frequently Asked Questions on Arithmetic Progression
What is the general form of Arithmetic Progression?
General Form of Arithmetic Progression (AP)
In an arithmetic progression (AP), the difference between any two consecutive terms is constant. This constant difference is known as the common difference (d).
The general form of an AP is:
a, a + d, a + 2d, a + 3d, ..., a + nd
where:
 a is the first term of the AP
 d is the common difference
 n is the number of terms in the AP
Examples:
 The sequence 1, 3, 5, 7, 9 is an AP with a = 1 and d = 2.
 The sequence 10, 7, 4, 1, 2 is an AP with a = 10 and d = 3.
 The sequence 0.5, 1, 1.5, 2, 2.5 is an AP with a = 0.5 and d = 0.5.
Properties of AP:
 The sum of the first n terms of an AP is given by the formula:
Sn = n/2(2a + (n  1)d)
 The nth term of an AP is given by the formula:
Tn = a + (n  1)d
 The common difference of an AP can be found by subtracting the first term from the second term, or by subtracting any two consecutive terms.
Applications of AP:
 APs are used in a variety of applications, including:
 Finding the sum of a series of numbers
 Calculating the average of a set of numbers
 Predicting future values based on past trends
 Solving problems involving interest rates and annuities
What is arithmetic progression? Give an example.
Arithmetic Progression
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is the same. This constant difference is called the common difference of the arithmetic progression.
The general formula for the nth term of an arithmetic progression is:
$$T_n = a + (n1)d$$
where:
 $$T_n$$ is the nth term of the arithmetic progression
 $$a$$ is the first term of the arithmetic progression
 $$d$$ is the common difference of the arithmetic progression
 $$n$$ is the number of the term
Example:
Consider the following sequence of numbers:
$$2, 5, 8, 11, 14, 17, 20$$
This sequence is an arithmetic progression with a common difference of 3. The first term of the sequence is 2, and the second term is 5. The difference between these two terms is 3. The third term is 8, and the difference between the second and third terms is also 3. This pattern continues for the rest of the sequence.
Applications of Arithmetic Progressions
Arithmetic progressions have a variety of applications in mathematics and other fields. Some examples include:
 In physics, arithmetic progressions are used to model the motion of objects in uniform acceleration.
 In finance, arithmetic progressions are used to calculate the future value of an investment.
 In statistics, arithmetic progressions are used to calculate the mean and standard deviation of a data set.
Arithmetic progressions are a fundamental concept in mathematics with a wide range of applications. By understanding the concept of arithmetic progressions, you can gain a deeper understanding of many different areas of mathematics and other fields.
How to find the sum of arithmetic progression?
How to Find the Sum of an Arithmetic Progression (AP)
An arithmetic progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is the same. For example, the sequence 1, 3, 5, 7, 9 is an AP with a common difference of 2.
The sum of an AP is the sum of all the numbers in the sequence. For example, the sum of the AP 1, 3, 5, 7, 9 is 1 + 3 + 5 + 7 + 9 = 25.
There are two formulas that can be used to find the sum of an AP:
 The sum of n terms of an AP is given by the formula:
Sn = n/2(2a + (n  1)d)
where:

Sn is the sum of the first n terms of the AP

a is the first term of the AP

d is the common difference of the AP

n is the number of terms in the AP

The sum of an infinite AP is given by the formula:
S = a/(1  r)
where:
 S is the sum of the infinite AP
 a is the first term of the AP
 r is the common ratio of the AP
Examples:
 Find the sum of the first 10 terms of the AP 1, 3, 5, 7, 9.
Sn = n/2(2a + (n  1)d)
Sn = 10/2(2(1) + (10  1)(2))
Sn = 5(2 + 9(2))
Sn = 5(20)
Sn = 100
Therefore, the sum of the first 10 terms of the AP 1, 3, 5, 7, 9 is 100.
 Find the sum of the infinite AP 1, 1/2, 1/4, 1/8, ….
S = a/(1  r)
S = 1/(1  1/2)
S = 1/(1/2)
S = 2
Therefore, the sum of the infinite AP 1, 1/2, 1/4, 1/8, …. is 2.
What are the types of progressions in Maths?
Progressions are sequences of numbers in which each term after the first is obtained by adding or subtracting a fixed number, called the common difference. There are three main types of progressions: arithmetic, geometric, and harmonic.
1. Arithmetic Progression (AP)
An arithmetic progression is a sequence of numbers in which the difference between any two consecutive terms is the same. The common difference can be positive or negative.
For example, the sequence 1, 3, 5, 7, 9 is an arithmetic progression with a common difference of 2.
The general formula for the nth term of an arithmetic progression is:
T_n = a + (n  1)d
where:
 T_n is the nth term of the progression
 a is the first term of the progression
 d is the common difference
2. Geometric Progression (GP)
A geometric progression is a sequence of numbers in which each term after the first is obtained by multiplying the previous term by a fixed number, called the common ratio. The common ratio can be positive or negative.
For example, the sequence 1, 2, 4, 8, 16 is a geometric progression with a common ratio of 2.
The general formula for the nth term of a geometric progression is:
T_n = ar^(n  1)
where:
 T_n is the nth term of the progression
 a is the first term of the progression
 r is the common ratio
3. Harmonic Progression (HP)
A harmonic progression is a sequence of numbers in which the reciprocals of the terms form an arithmetic progression.
For example, the sequence 1, 1/2, 1/3, 1/4, 1/5 is a harmonic progression.
The general formula for the nth term of a harmonic progression is:
T_n = 1/(a + (n  1)d)
where:
 T_n is the nth term of the progression
 a is the first term of the progression
 d is the common difference of the reciprocals of the terms
Examples of Progressions in Real Life
Progressions are used in a variety of reallife applications, including:
 Finance: The interest on a loan or investment can be calculated using an arithmetic progression.
 Physics: The distance traveled by an object in motion can be calculated using a geometric progression.
 Music: The notes in a musical scale form a harmonic progression.
Progressions are a powerful tool for modeling and understanding a variety of phenomena in the real world.
What is the use of Arithmetic Progression?
Arithmetic Progression (AP) is a sequence of numbers in which the difference between any two consecutive numbers is the same. This constant difference is known as the common difference (d). The general formula for the nth term of an AP is:
nth term = first term + (n  1) * common difference
For example, consider the AP 2, 5, 8, 11, 14, …. Here, the first term (a) is 2, and the common difference (d) is 3. The 10th term of this AP can be calculated as:
10th term = 2 + (10  1) * 3 10th term = 2 + 9 * 3 10th term = 2 + 27 10th term = 29
APs have various applications in different fields:

Mathematics: APs are used to study sequences and series, as well as to solve problems involving summation of terms.

Physics: APs are used to describe motion with constant acceleration. For example, if an object is moving with an initial velocity (u) and constant acceleration (a), then the distance (s) traveled by the object after time (t) is given by the formula:
s = u * t + 0.5 * a * t^2
This formula is derived using AP.
 Finance: APs are used to calculate compound interest. In compound interest, the interest earned in each year is added to the principal amount, and interest is calculated on the increased amount in subsequent years. The formula for compound interest is:
A = P * (1 + r/n)^(n*t)
where: A = final amount P = principal amount r = annual interest rate n = number of times interest is compounded per year t = number of years

Statistics: APs are used to calculate measures of central tendency, such as mean, median, and mode.

Engineering: APs are used in various engineering applications, such as calculating the forces acting on structures and designing gears and pulleys.
In summary, Arithmetic Progression is a useful concept with applications in various fields, including mathematics, physics, finance, statistics, and engineering.