[Maths Class Notes] on Variable Definition Pdf for Exam

What is a Variable?

Mathematics consists of an algebraic expression that has a combination of constants, variables, coefficients and fundamental operations like addition, division, subtraction, and multiplication. Every single term constitutes the basis of algebra.

While studying Algebra, one will find an alphabet that is used to portray an unknown number. The alphabet represents value. Variable quantities might be changed by the given mathematical problem. The most generally used variables are x, y, and z. In simpler terms, a variable stands as a symbol for an unknown number whose value is not given.

For example, 

x + 8 = 16; “x” here acts as a variable.

The value of the “x” variable can easily be found by working out the problem. Here the value of “x” will be 8 that means x=8.

The term variable is also used in subjects like statistics. Variables in statistics are referred to as data items. The variable represents numbers/characteristics which could be measured. Example, age, income, sex, capital expenditure, etc. are few such variable examples available in statistics.

Different Types of Variables 

There are many types of variables but we will discuss roughly three different variables. Different Types of Variables in Maths:

1. Dependent Variables:

 A dependent variable is the type of variable that generally tends to depend on the values of other numbers or variables. Precisely, a dependent variable often acts as the output of a function. 

The change in the value of an independent variable affects the change of the dependent variable as it is dependent on it. That is so because the value of the dependent variable depends on what is put into the function.

Example: y= 5 + 3x

Here, y acts as a dependent variable and thus is called so. The value of y depends completely on the function 5 + 3x

2. Independent Variable:

An Independent variable is the type of variable that generally tends to not depend on the value functions of other variables or numbers. It is also known as the input of a function. The dependent variable depends on this variable i.e the independent variable for its value.

Example: x = 3y + 4z

Here, x refers to a dependent variable

y and z act as the independent variables because y and z values do not get affected by other values.

Types of Variable in Research

Qualitative Variables:

Two variables differ in qualitative factors and quantitative factors. Qualitative variables are the variables that are used to express qualitative attributes namely hair colour, race, religion, social caste, gender, method payment, etc.

Qualitative variables are often known as Categorical Variables.

Example: There are two different categories in variable sex namely ‘male’ and ‘female’. As the variable values are expressed in different categories, it is referred to as a categorical variable.