JEE Exam » JEE Study Material » Mathematics » How to Solve Inequality Problems

How to Solve Inequality Problems

In this article we are going to discuss how to graph inequality and how to solve inequality related problems in mathematics.

In mathematics, an inequality is a mathematical expression that has two sides that are not equal. In mathematics, inequality occurs when a connection makes a non-equal comparison between two expressions or two numbers. In this situation, the inequality symbols greater than symbol (>), less than symbol (<), greater than or equal to symbol (≥), less than or equal to symbol (≤), or not equal to symbol (≠) substitute the equal sign “=” in the expression. Polynomial inequality, rational inequality, and absolute value inequality are examples of inequalities in mathematics.

Strict inequalities are represented by the symbols < and >, while slack inequalities are represented by the symbols ≤ and ≥. A linear inequality looks precisely like a linear equation, but the symbol that connects two expressions is different.

Linear equality

The graphical approach of solving linear inequalities is a simple way to obtain solutions for linear equations. It’s easy to solve a one-variable linear equation by plotting the value on a number line. For two-variable scenarios, however, the graph must be plotted in an x-y plane. A linear function is used in linear inequality. An equation is a mathematical expression that contains the equal-to (=) symbol. The equality symbol indicates that the right-hand side of the phrase is the same as the left-hand side. Inequalities are created when two mathematical expressions contain symbols such as greater (>), less than(<), greater than or equal (≥), less than or equal (≤).

For instance,

Statement 1— Neeta is 15 years old.

The mathematical expression for the equality symbol is x = 15.

Statement 2 — If I assert that Neeta is at least 15 years old, then this can be written as x ≥ 15.

As a result, Statement 1 is an equation, while Statement 2 is an inequality.

Solving Linear Inequality

Let’s talk about how to solve inequalities graphically immediately. A straight line is the graph of a linear equation, and any point in the Cartesian plane with regard to it will lie on either side of it. Consider the expression ax + by for a two-variable linear equation. This statement can be used to represent the following inequalities.

  1. ax + by < c

  2. ax + by ≤ c

  3. ax + by > c

  4. ax + by ≥ c

Consider the line ax + by = c, a ≠ 0 and b ≠ 0 to solve these inequalities. This line’s graph may be seen below: 

The graph of the line splits the Cartesian plane into two parts. All points (x, y) on the line axe + by = c satisfy the equation, indicating that both sides of the equation are equal. A solution to the line is represented by the point (α,β) on the line ax + by = c. Thus, aα + bβ = c.

Consider the upper half of the plane and the N(α, ϒ). The graph clearly indicates that ϒ >β. Also, because the graph is represented as a straight line, it indicates that b>0; otherwise, the equation ax + by = c would just be a point.

⇒ bϒ > bβ

⇒ aα + bϒ > aα + bβ 

⇒ aα + bϒ > c

Any point Q(α, ϒ) above or in the upper half of the plane, or the region denoted by I produced by the line ax + by = c, would meet the inequality ax + by > c.

Linear Inequalities Graphing

  • ax + by < 0 and ax + by > 0

The region designated II, which is below the line ax + by = c, contains all the points that satisfy the inequality ax + by < c. As a result, zone II is the solution region for the inequality of type ax + by < c. The line ax + by = c is dotted because it is outside of the solution zone.

All of the points that fulfil the inequality ax + by > c are found in the top half of the line ax + by = c, or the region indicated I. As a result, Zone I is the solution region for the inequality ax + by > c. The line ax + by = c is dotted because it is outside of the solution zone.

  • ax + by ≤ 0 and ax + by ≥ 0

All points that meet the inequality ax + by ≤ c are found in the region labelled II, which is below and includes the line ax + by = c. As a result, Zone II is the solution region for the inequality of type ax + by ≤ c.

All points that meet the inequality ax + by ≥ c are found in the region below and including the line ax + by = c, or the region labelled I. As a result, Zone I is the solution region for the inequality of type ax + by ≥ c.

Conclusion

Therefore we can finally conclude that strict inequalities are represented by the symbols < and >, while slack inequalities are represented by the symbols ≤ and ≥. A linear inequality looks precisely like a linear equation, but the symbol that connects two expressions is different. The graphical approach of solving linear inequalities is a simple way to obtain solutions for linear equations. It’s easy to solve a one-variable linear equation by plotting the value on a number line. For two-variable scenarios, however, the graph must be plotted in an x-y plane. A linear function is used in linear inequality.

faq

Frequently asked questions

Get answers to the most common queries related to the JEE Examination Preparation.

What does it mean to be unequal?

Ans. An inequality is a relationship between two real numbers or algebraic expressions that use the symbols > , &...Read full

What do the various inequality symbols mean?

Ans. In mathematics, there are three types of inequality: not equal (≠), strict inequalities ( > , < ), and ...Read full

Mention the properties of inequality .

Ans. Inequalities have the following characteristics: ...Read full

Mention the inequalities-solving rules.

Ans. The following rules have no bearing on inequality direction: On bo...Read full

Is it possible to shift the direction of inequality by changing the values on the left and right sides?

Ans. Yes, changing the values on the left and right sides of the inequality alters its direction.