Quadratic Functions and Equations in One Variable
Variable
A symbol, usually a letter, standing for a number that can change.
| English | Variable |
|---|---|
| Bahasa Melayu | Pemboleh ubah |
| 中文 | 变量 |
How it is used
In the quadratic y = x² − 4x + 3, x is the variable: choosing x = 0 gives y = 3, and choosing x = 4 gives y = 3 again, showing how y changes as the variable x changes.
Where it shows up in SPM
A foundational idea across all of SPM Mathematics, and here the letter x whose value we solve for or vary (Form 4). In Paper 2 you tabulate values of the variable to plot a graph, or solve for the variable that satisfies an equation.
Don't confuse it with
Open the chapter: Quadratic Functions and Equations in One Variable →
Frequently asked questions
In y = ax² + bx + c, which letters are variables?
x and y are the variables that change together, while a, b and c are constants fixed for a particular function. For a specific quadratic such as y = 2x² − 4x + 1, only x and y vary; a = 2, b = −4 and c = 1 stay the same.
Does a variable always have to be x?
No. Any letter can be a variable, questions often use t for time or p for a price.
The letter is just a name; what matters is that it stands for a quantity that can change while you work with the equation.