Solving a cubic equation is similar in some aspects to solving a quadratic equation, factorisation is in action.
In the two videos, I show you the step by step approach I took to solve a cubic equation either by synthetic division or comparing coefficients.
This concept is usually covered in Secondary 3 Additional Maths syllabus under Factor and Remainder Theorem.
Step 1 (same for both methods) : Guess and Check the first factor (with the help of the calculator).
Step 2: Find the Quadratic Factor.
Leave a comment to share with me which method do you prefer or usually use? I look forward to your comment!
Video 1: GCE O-Level A-Maths: Solve a Cubic Equation by Synthetic Division
Direct link: http://www.youtube.com/watch?v=4rWHMmKh-aM
Video 2: GCE O-Level A-Maths: Solve a Cubic Equation by Comparing Coefficients
Direct link: http://www.youtube.com/watch?v=IIxFHhX65Zg