Study Notes
Equations and inequalities involve solving for unknown values using algebraic methods and graphical interpretations. This topic covers linear and quadratic equations and inequalities, including their solutions and graphical representations.
- Linear simultaneous equations — a system of two or more linear equations solved together to find a common solution. Example: x + 3y = 11 and 4x - 5y = 10 solved to x = 5, y = 2.
- Quadratic simultaneous equations — a system involving one linear and one quadratic equation solved together. Example: y - x = 5 and y = x² + 3x + 2 solved to x = -3 or x = 1.
- Linear inequalities — expressions showing the relationship of inequality between two expressions. Example: x < 4 represented on a number line.
- Quadratic inequalities — inequalities involving quadratic expressions, often solved by graphing. Example: 2x² + 5x + 3 ≥ 1.
- Regions — areas on a graph that satisfy a set of inequalities. Example: y < f(x) represents points below the curve y = f(x).
Exam Tips
Key Definitions to Remember
- Linear simultaneous equations
- Quadratic simultaneous equations
- Linear inequalities
- Quadratic inequalities
Common Confusions
- Mixing up the methods for solving linear and quadratic equations
- Forgetting to use solid or dashed lines for inequalities on graphs
Typical Exam Questions
- Solve the simultaneous equations x + 3y = 11 and 4x - 5y = 10? x = 5, y = 2
- Find the set of values of x for which 5x − 3 ≤ 2x + 18? x ≤ 7
- Solve the inequality x² - x - 2 > 0? x < -1 or x > 2
What Examiners Usually Test
- Ability to solve and interpret simultaneous equations
- Understanding of graphical representation of inequalities
- Correct application of solving methods for different types of equations