The intervals where concave up/down are also indicated. If the concavity of f changes at a point (c,f(c)), then f′ is changing from increasing to decreasing (or, decreasing to increasing) at x=c. That means that the sign of f″ is changing from positive to negative (or, negative to positive) at x=c.

What is the name of the point where concavity changes?

Inflection points are points where the function changes concavity, i.e. from being "concave up" to being "concave down" or vice versa. They can be found by considering where the second derivative changes signs.

What marks the change in the curve concavity?

Answer: Concavity relates to the rate of change of a function's derivative. ... Similarly, f is concave down (or downwards) where the derivative f′ is decreasing (or equivalently, f′′f, start superscript, prime, prime, end superscript is negative).