Summary
Numerical methods are techniques used to find approximate solutions to equations. These methods involve finding a starting point and improving the solution using iterative processes.
- Graphical Approach — A method to find a starting point by sketching graphs to determine the number of real roots. Example: The graphs intersect at 3 points, indicating 3 roots for the equation.
- Change of Sign Approach — A method to find a starting point by checking for a sign change in a continuous function. Example: If f(-1) and f(0) have opposite signs, there is a root between -1 and 0.
- Iterative Formula — A process to improve the solution by repeatedly applying a formula to get closer to the root. Example: Using x₀ = 2, the iterative process finds the solution to x³ + 3x = 21 to 3 decimal places.
Exam Tips
Key Definitions to Remember
- Graphical Approach: Using graphs to find the number of real roots.
- Change of Sign Approach: Checking for sign changes in a continuous function to locate roots.
- Iterative Formula: A repeated process to refine the solution to an equation.
Common Confusions
- Confusing the graphical approach with the iterative process.
- Misunderstanding the concept of convergence in iterative methods.
Typical Exam Questions
- How do you find a root using the change of sign method? Check for sign changes in the interval.
- What is the purpose of an iterative formula? To refine the solution to a desired accuracy.
- How do you determine the number of roots using graphs? Count the points of intersection of the graphs.
What Examiners Usually Test
- Ability to apply numerical methods to find roots.
- Understanding of iterative processes and convergence.
- Skill in using graphical and sign change methods to locate roots.