Mathematics

Mathematics is the base of human civilization. From cutting vegetables to arranging books on the shelves, from tailoring clothes to motion of Planets - Mathematics applies everywhere.

Number SystemCalculus | Probability | Trigonometry | Geometry & Mensuration | Algebra & Arithmetic | Coordinate Geometry

A coordinate geometry is a branch of geometry where the position of the points on the plane is defined with the help of an ordered pair of numbers also known as coordinates.

Algebra is the study of mathematical symbols and the rules for manipulating these symbols. Arithmetic is a branch of mathematics that consists of the study of numbers, especially the properties of the traditional operations on them - addition, subtraction, multiplication and division.

Geometry is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. Mensuration is the part of geometry concerned with ascertaining lengths, areas, and volumes.

Trigonometry is a word derived from three Greek words - Tri meaning Three, Gon meaning Sides and Metron meaning to measure. Trigonometry is the study of relationships between the sides and angles of a triangle.

The word chance, possible, probably or likely convey some sense of uncertainty about the occurrence of some events. The entire world is filled with uncertainty. You make decisions affected by uncertainty virtually every day.

Calculus is that branch of Mathematics that deals with the study of change in the value of a function as the points in the domain change.

From time immemorial human beings have been trying to have a count of their belongings- goods, ornaments, jewels, animals, trees, sheeps or goats, etc. by using various techniques. One of the greatest inventions in the history of civilization is the creation of numbers.

1. Addition of Rational Numbers

(a) Consider the addition of rational numbers with same denominators: p/q and r/q

When an integer a is divided by another non-zero integer b. The following cases arise:

While dealing with natural numbers and whole numbers, it is not always possible to subtract a number from another. For example, (2 – 3), (3 – 7), and (9 – 20) are all not possible in the system of natural numbers and whole numbers. Thus, it needed another extension of numbers which allow such subtractions.

The counting numbers 1, 2, 3, ... constitute the system of natural numbers. These are the numbers which are used in day-to-day life.

Counting things is easy now. You can count objects in large numbers and represent them through numerals. It is not as if we always knew how to convey large quantities in conversation or through symbols. Many thousands years ago, people knew only small numbers.

The term ‘Geometry’ is the English equivalent of the Greek word ‘Geometron’. ‘Geo’ means Earth and ‘metron’ means Measurement. According to historians, the geometrical ideas shaped up in ancient times, probably due to the need in art, architecture and measurement. These include occasions when the boundaries of cultivated lands had to be marked without giving room for complaints.

When a number is expressed as a product of its factors, the number is said to be factorised.

You can find a pattern that can tell whether a number is divisible by 2, 3, 4, 5, 6, 8, 9, 10 or 11.

In the numbers 2, 4, 6, 8, 10, 12, 14, ... each of them is a multiple of 2. These are called even numbers.

There are numbers, having exactly two factors 1 and the number itself. Such number are 2, 3, 5, 7, 11, and so on. These numbers are prime numbers.

You can find the common factors of any two numbers. For example, the common factors of 12 and 16 are 1, 2 and 4. The highest of these common factors is 4.

The Lowest Common Multiple (LCM) of two or more given numbers is the lowest (or smallest or least) of their common multiples. For example, the common multiples of 4 and 6 are 12, 24, 36, ... . The lowest of these is 12. So, the lowest common multiple of 4 and 6 is 12.

A factor of a number is an exact divisor of that number. For example, 1, 2, 3 and 6 are exact divisors of 6. They are called the factors of 6.

Given any natural number, you can add 1 to that number and get the next number i.e. you get its successor. The successor of 16 is 16 + 1 = 17, that of 19 is 19 +1 = 20 and so on. The number 16 comes before 17, we say that the predecessor of 17 is 17 – 1 = 16, the predecessor of 20 is 20 – 1 = 19, and so on. Does 1 have both a successor and a predecessor?

Arithmetic Mean

A is called the arithmetic mean of the numbers a and b if and only if a, A, b are in AP.

A sequence of non-zero numbers is said to be in harmonic progression (HP) if their reciprocals are in AP.

A geometric progression (GP) is a sequence of numbers in which the first term is non-zero and each term, except the first, is obtained by multiplying the term immediately preceding it by a fixed non-zero number. This fixed number is called the common ratio and it is denoted by r.

An arithmetic progression (AP) is a sequence of numbers in which each term, except the first, is obtained by adding a fixed number to the immediately preceding term. This fixed number is called the common difference, which is generally denoted by d.

A Binomial is an algebraic expression of two terms which are connected by the operation: + or −.

Induction is the process of inferring a general statement from the truth of particular cases.

The word combination means selection. Suppose you are asked to make a selection of any two things from three things: a, b and c.

A circular permutation is one in which the things are arranged along a circle. It is also called closed permutation.

The number of permutations of n different things, taken r at a time, when each may be repeated any number of times in each arrangement, is nr.

The number of mutually distinguishable permutations of n things, taken all at a time, of which p are alike of one kind, q alike of second such that p + q = n, is n!/p! q!.

The scalar product of two vectors is a scalar quantity. Therefore, the product is called scalar product.

Any three numbers proportional to direction cosines of a vector are called its direction ratios.

Let P(x, y, z) be any point in space with reference to a rectangular coordinate system O (XYZ). Let α, β and γ be the angles made by OP with the positive direction of coordinate axes OX, OY, OZ respectively. Then cos α, cos β, cos γ are called the direction cosines.

If P is a point in a two dimensional plane which has coordinates (x, y).

Triangle Law of Addition of Vectors

Triangle Law of Addition of vectors states that, if two vectors are represented in magnitude and direction by the two sides of a triangle taken in the same order, then their sum is represented by the third side taken in the reverse order.

Zero or Null Vector

A vector whose initial and terminal points are coincident is called a zero or null or a void vector. The zero vector is denoted by .

Physical quantities are divided into two categories: Scalar quantities and Vector quantities.

The quantities sin−1x, cos−1x, tan−1x are called inverse circular functions. sin−1x is an angle θ, whose sine is x.

A triangle has six parts or elements - the sides a, b, c and the angles A, B, C.

In any triangle ABC, area of the triangle is

In any triangle ABC,

a/sinA = b/sin B = c/sinC = 2R