# PRE RMO

This Category will divide the articles that are useful for jee Advanced Exam. This could include theory, solved examples, unsolved examples, test papers and previous year papers.

## Principle of Inclusion and Exclusion – with Examples

Principle of Inclusion and Exclusion (PIE) To understand inclusion exclusion principle, lets take an example Suppose there is a class of students who speak 3 languages. English, Spanish and French.  Each student speaks at least one of the languages. Let E be the set of the students speaking English, set S stands for Spanish speaking …

## How to find number of divisor of any integer

Number of divisor   If you are interested in knowing how to find out number of Divisor for any number n then stay tuned. Let’s understand some basic terms first   What is a divisor: A number p (positive integer) is said to be a divisor of number n (positive integer) if and only if …

## Arithmetic Geometric Series and other Summation Techniques

Do you want to know what is Arithmetic Geometric Series ? Or how to find its sum? Or what is difference method and other summation techniques? Let’s begin with AGP. If are new to sequences and series, you must begin from Arithmetic Progression     Arithmetic  Geometric Series   If is an A.P. and is …

## Relation between Arithmetic, Geometric and Harmonic Progressions

Do you want to know how Arithmetic Geometric and Harmonic progressions are linked to Each other? Well there are many ways in which they are related. Let’s know all of them.   If you Don’t Know about Arithmetic Geometric and Harmonic Progression you can Read here Harmonic Progression          (1) If A, …

## Rational Root theorem : Concept, Proof and Examples

Do you want to know what is Rational root theorem? Or you looking for its proof? This post will cover not only theorem and its proof but also how to use this to find roots of polynomial equation. What is Rational Root theorem Statement: Let anxn + an-1xn–1 + … + a1x + a0 = …

## Graph Range and Sign of quadratic expression

To understand Quadratic equations further we must know graph, Range and Sign of Quadratic expression. These three concepts sometimes becomes the major part of the questions when hunting for roots doesn’t make more sense. What is a quadratic expression An expression of the form , where a,b,c are real number and a is non zero …

## Sine rule cosine rule and Napiers analogy : Formula and examples

Are you willing to understand sine rule cosine rule and law of tangents. These three laws are very important properties of a triangle. I have added some good number of examples to make things pretty clear. If you are new to trigonometry, I recommend you to read Trigonometric Ratios and Identity The Law of sines …

## Arithmetic Geometric and Harmonic mean Formula and Examples

Are you looking forward to understand what is arithmetic mean, geometric mean and harmonic mean? Or how are they related to each other? This post covers in depth understanding of AM,GM and HM. Before you read ahead make sure you are well versed with Arithmetic progression Geometric progression Harmonic progression If you have basic understanding …

## Solving trigonometric equations of different types with examples

Have you ever been stuck in a question which requires understanding on how to solve trigonometric equations. Well all trig equations are not that straightforward. Some requires deeper understanding of identities and formula. Let’s start with basics. What is a trigonometric Equation? An equation involving one or more trigonometric ratio of an unknown angle is …

## Binomial Theorem Expansion : Formula and examples

You might have used the formula , but do you know what would be the formula for or . Binomial theorem expansion formula explains this for all real n.  Let’s understand some basic terms first. What is Binomial Expression A binomial expression is an algebraic expression consisting of two terms with +or –  sign between …

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