Monotonicity from sign of derivative (f' > 0 on interval ⇒ f strictly increasing; f' < 0 ⇒ strictly decreasing)
jee-mainjee-advanced
f' > 0 on interval ⇒ f strictly increasing; f' < 0 ⇒ strictly decreasing
What each symbol means
| Symbol | What it stands for |
|---|---|
| f'(x) | Derivative on open interval I |
When to use this
f continuous on I and differentiable on interior (standard JEE use). f'=0 at isolated points can still allow strict increase if f'≥0 and only discrete zeros.