IB Maths AI SL 5.2 Increasing & decreasing functions
IB Maths AI SL 5.2 Increasing & decreasing functions
Students practise using the sign of f′(x) to determine intervals where a function increases or decreases—and justify conclusions using derivative values or graphs.
How this is tested
- evaluate f′(3.5) and confirm it is positive to show f(x) is increasing at that point
- read the interval where f′(x) > 0 from a graph or solve f′(x) > 0 algebraically to give x > 4 or (4, ∞)
- compare the maximum value of h′(x) against a safety threshold (e.g., 0.2) to assess compliance