Simple Inequalities (Linear and Quadratic)
Simple Inequalities (Linear and Quadratic)
Overview
- Inequalities represent a relationship between quantities, stating that one is greater than, less than, or equal to another.
- Simple inequalities are part of the wider spectrum of inequalities and include linear and quadratic inequalities.
Linear Inequalities
- A linear inequality looks much like a linear equation, but with an inequality sign instead of an equals sign.
- Linear inequalities can be solved in a similar way to linear equations.
- Examples of linear inequalities include
x + 3 > 7
or2y - 4 ≤ 8
.
Quadratic Inequalities
- Quadratic inequalities are inequalities that involve a quadratic expression, such as
x^2 + 3x - 10 > 0
. - The graph of a quadratic inequality is a parabola which can be useful in understanding and solving quadratic inequalities.
Solving Simple Inequalities
- To solve a simple inequality, the aim is to isolate the variable.
- Basic operations such as adding, subtracting, multiplying, and dividing can be performed on both sides of an inequality, much like in an equation.
- When multiplying or dividing by a negative number, the direction of the inequality sign must be reversed.
- For quadratic inequalities, solutions are often found by first solving the corresponding quadratic equation, and then deciding on the appropriate range for the variable.
Applying Inequalities
- Inequalities can be used to represent various real-world situations where there is a range of possible solutions.
- For example, inequalities can be used to model situations involving budgets, limits, or any situation where there may be a minimum or maximum limit.
Common Pitfalls
- Always remember to flip the inequality sign when multiplying or dividing by negative numbers.
- When solving quadratic inequalities, remember that the solution may be a range of values, not a specific value.
- Avoid ambiguity by always using clear notation, especially when dealing with compound inequalities.
Practise Problems
- Try out numerous problems involving linear and quadratic inequalities to hone your skills.
- Problems should include both algebraic and word problems to provide a wide range of practice.
- Solving inequalities should involve performing operations correctly, using clear notation, and correctly interpreting inequality statements. Be assured that practice in this area will build a solid foundation in understanding and solving inequalities.