First derivative test for local extrema (f' changes + to - at c → local max; - to + → local min)
jee-mainjee-advanced
f' changes + to - at c → local max; - to + → local min
What each symbol means
| Symbol | What it stands for |
|---|---|
| c | Critical point (f'(c)=0 or f' undefined) |
When to use this
f continuous at c and differentiable on punctured neighborhood; sign change of f' across c.