Inequalities

Inequalities Overview

  • Inequalities are mathematical statements used to compare expressions and include symbols like ‘<’, ‘>’, ‘≤’, and ‘≥’.
  • Unlike equations, inequalities define a range of solutions rather than a specific solution.

Solving Inequalities

  • Solving inequalities is like solving equations, with the goal to isolate the variable.
  • Use the BIDMAS order to undertake operations while solving the inequality.
  • For instance, to solve the inequality 3x > 12, divide both sides by 3 to get x > 4, means that all values of x greater than 4 satisfy the inequality.
  • Important to remember, when an inequality is multiplied or divided by a negative number, the inequality sign must be reversed.

Graphical Representation of Inequalities

  • Inequalities can be represented graphically.
  • A dashed line indicates a “less than” (<) or a “greater than” (>) inequality, meaning points on the line are not part of the solution.
  • A solid line is used for “less than or equal to” (≤) or “greater than or equal to” (≥) inequalities, meaning points on the line are included in the solution.
  • Shading is used to illustrate the solution set for the inequality.
  • For instance, region above the line is shaded when the y-value is greater than the x-value, and vice versa.

Compound Inequalities

  • Compound inequalities are two or more inequalities joined together by “and” or “or”.
  • When “and” is used, the solution of the inequality is where the solution sets of the two inequalities overlap.
  • When “or” is used, the solution set includes any solutions of either inequality.

Revision and Practice

  • Ensure you check your solutions by substitifying values into the original inequality to ensure it holds true.
  • Consistent practice in solving and graphing inequalities improves comprehension and proficiency. Apply different inequality problems to hone these skills.

Remember, inequalities provide a versatile tool for solving a variety of algebraic problems and understanding how different quantities relate and contrast to one another.