Points of Inflection (AQA A-Level Mathematics): Flashcards

A point where the graph changes concavity (concave up ↔ concave down)

$f''(x)$ changes sign at $x = c$

$f''(x) < 0$

$f''(x) > 0$

Find second derivative $f''(x)$

If $f''(x)$ changes sign around that point

No, must check for sign change in $f''(x)$

$(0, 0)$

No, $f''(x)$ doesn't change sign

Check sign of $f''(x)$ before and after the point