# Mathematical relationship between two variables for the given

### What are the different types of mathematical relationships?

Complete correlation between two variables is expressed by either + 1 or The data are given in table and the scatter diagram shown in figure Each dot Figure Scatter diagram of relation in 15 children between height and. Describing Relationships between Two Variables. Up until now, we have any relationship here. People of a given height can be any age. Some guidelines. --When dealing with a relation, the x and y variables have particular roles to play. See how relationships between two variables like number of toppings and cost of The three main ways to represent a relationship in math are using a table.

## Variables, Functions and Equations

Here there are two variables: Independent variables are those which do not depend on other variables. Dependent variables are those which are changed by the independent variables. The change is caused by the independent variable. In our example salary is the independent variable and the amount you spend is the dependent variable. To continue with the same example what if the amount you choose to spend depends not only on your salary but also on the income you receive from investments in the stock market.

Now there are three variables: A function is a mathematical relationship in which the values of a single dependent variable are determined by the values of one or more independent variables. Function means the dependent variable is determined by the independent variable s. A goal of economic analysis is to determine the independent variable s which explain certain dependent variables.

For example what explains changes in employment, in consumer spending, in business investment etc.? Functions with a single independent variable are called univariate functions. There is a one to one correspondence. Functions with more than one independent variable are called multivariate functions.

The independent variable is often designated by x. The dependent variable is often designated by y. We say y is a function of x. This means y depends on or is determined by x. If we know the value of x, then we can find the value of y.

In pronunciation we say " y is f of x. In other words the parenthesis does not mean that f is multiplied by x.

It is not necessary to use the letter f. We may look at functions algebraically or graphically. If we use algebra we look at equations.

## Modeling with tables, equations, and graphs

If we use geometry we use graphs. There is one dependent variable, the price of pizza and there are three independent variables, the prices of tomato sauce, cheese, and pizza dough. It says that the quantity of pizza demanded depends on the price of pizza and the number of potential pizza eaters.

There is one dependent variable, the quantity of pizza demanded, and there are two independent variables, the price of pizza and the number of potential pizza eaters. This is a very general form of the consumption function. In order to use it economists must put it into a more precise mathematical form. The use of functional notation: The independent variable, x, can have different values.

When x changes y also changes. This means find the value of y when x equals 0. This means find the value of y when x equals 1. This means find the value of y when x equals It says that demand depends on price. Example 3 Two or more functions can be added, subtracted, multiplied or divided.

For example, gas mileage and the weight of a car are negatively related, because heavier cars tend to get lower mileage.

Linear and Nonlinear Relationships Two variables may be related linearly.

**Two-variable linear equations and their graphs - Algebra I - Khan Academy**

This means that a straight line can represent their relationship. For example, the amount of paint needed to paint a wall is linearly related to the area of the wall. Other relationships cannot be represented by a straight line. These are called nonlinear. For example, the relationship between height and weight in humans is nonlinear, because doubling height usually more than doubles weight.

For example, a child may be three feet tall and weigh 50 pounds, but probably no six-foot tall adult weighs only pounds. A monotonic relationship is one where the relationship is either positive or negative at all levels of the variables.

A non-monotonic relationship is one where this is not so. All of the examples above were monotonic.

### Types of Mathematical Relationships Between Two Variables | Sciencing

An example of a non-monotonic relationship is that between stress and performance. People with a moderate amount of stress perform better than those with very little stress or those that have a great deal of stress. Strong and Weak Relationships A relationship between two variables may be strong or weak.