The variation of a function means the rate at which a certain function changes. The rate of variation of a function is also called the slope.
According to the mathematical definition, the slope represents the change of the function by increasing the value of by .
- If the function's graph is represented by a straight line, it means that the rate of variation of the function is constant
- However, if the graph is not represented by a straight line, this implies that the rate of variation of the function is not constant