Solving and graphing linear inequalities with a calculator is nearly the same in theory as other linear equations, except the problem replaces the “=” comparison with a symbol representing inequality, such as < and >, Integers that are not equal contain a property referred to as inequality.

A simple algebraic example of an equation representing inequalities is y<4x+5.

Graphing typically involves the values of ordered pairs to identify the coordinates in order to plot x and y coordinates on a plane. The order of the coordinates is critical in representing the equation to be solved in the graphic representation, since changing the order would provide a different result.

The first number in an ordered pair represents the horizontal direction, while the second value refers to the vertical direction on the axes.

Learning the fundamentals for solving and graphing inequalities is a wise first step before working with templates or your calculator to perform those functions. __Math Is Fun__ offers a primer for understanding the concept, including multiple examples, exercises, and calculator command steps.

Graphing linear inequalities without the use of a calculator can be challenging and prone to errors. It is to your advantage to utilize a scientific graphing calculator to solve such equations accurately.

**Putting the Calculator’s Features to Use**

Powerful graphing calculators such as TI’s family of 83/84 models make solving linear equations and graphing inequalities an easy task.

Users experienced with these tools __provide tips__ that those less familiar with the process can benefit from. Detailed steps are provided that guide calculator users through not only how to enter the values and formula, but even the keys/functions to be utilized to accomplish the solution.

These TI calculators graph inequalities in two variables by shading the portion of the screen either below or above the graph of your equation. TI also provides an app especially for graphing inequalities – Inequalz App. This app comes preloaded on the TI 84 Plus, ready to go. It can also be downloaded for use on the TI 83 Plus.

__Dummies.com__ provides a variety of tips for using TI 83/84 menus and functions, accelerating the learning process.

__Casio’s fx-9750GII__ is another powerful calculator capable of graphing inequalities with built-in functions. No additional app is needed. Casio also publicized advantages over competitors such as the reduction in keystrokes required for the function, and enhanced information provided such as tracing of inequalities and intersection points found.

Other models by these manufacturers, as well as graphing calculators made by other companies provide similar capabilities. These models are presented only as examples of devices that offer extensive graphing features including inequalities.

**Use the Power of the Web**

There are a number of graphing linear inequalities calculators on the web, if you want to gain an understanding of the algebra required in solving these equations, but don’t plan on needing the function on a regular basis.

__Calculator TutorVista__ is a good example of what’s available as a teaching exercise as well as providing a usable site for calculating solutions.

If graphing inequalities will be in your future for some time, investing in a calculator that’s up to the task is definitely worthwhile.

**Graphing Inequalities on a Number Line**

Generating and graphing inequalities on a number line calculator can be accomplished in a similar manner as graphing a number, as represented on the __Math Warehouse web site__. Examples are provided that provide a thorough understanding of the steps required, including examples.

**Alternatives – There’s an App for That**

Remember that your smartphone is actually a reasonably powerful computer, as well. Although they are not endowed with built-in calculators of the scientific/graphing genre, there are plenty of apps available for download that may solve many of your graphing and linear equation requirements.

The __iTunes app store__ has a variety of apps available for scientific calculator use, as does the __Google Play store__ for Android devices.

Some of these applications are totally free, while others are available at minimal cost.

**Opinions and Reviews**

Browsing the internet for reviews by customers of the TI 83/84 models reveals a generally positive opinion. On Amazon alone, there are 162 positive reviews and 50 critical opinions. Most of the downsides are related to clarity or visibility of the display itself, with most consumers quite satisfied with the functionality and reliability of the calculator.

Casio purchasers were a bit more enthusiastic about their purchases, taking into account the functionality, reliability, and notably – the price.

To no one’s surprise, purchasers of the higher-priced TI units tend to be professionals such as teachers or engineers, while the Casio models are more commonly purchased by students, at various grade levels.

When making such an investment, consider your own needs, do your homework on functions, price, and reviews. You are then prepared to make an educated choice.

Feature image via YouTube

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