This is what we call a point on f(x) where the first derivative f'(x) = 0.
What is a critical point?
This is what we call a point on f(x) when the second derivative f"(x) changes sign.
What is an inflection point?
The graph shown is f'(x). This is where f is concave down.

What is
(-infty , -3) ?
The original function f(x) does this when the derivative f'(x) is negative.
What is decreases?
An inflection point is where the graph of f(x) does this.
What is changes concavity?
The graph of f(x) is shown. This is where f'(x) > 0 and f"(x) < 0.
What is the interval (-1,0) ?
This is what we call a point on f(x) when the first derivative f'(x) changes from increasing to decreasing.
What is relative maximum?
This is what we call an interval on f(x) when f"(x) is positive.
What is concave up?
This is the order of f(-3), f'(-3), and f"(-3) from least to greatest.
What is f"(-3) < f(-3) < f'(-3) ?
These are the critical numbers of
f(x) = 3x^3+12x^2-36x.
What are x = 0, 2, and -6?
These are the inflection points of
f(x) = 1/2x^4-12x^2+18x.
What are x = 2 and x = -2 ?
These are the x coordinates of the critical points of f.

What are x = 1 and x = 2 ?
The graph of f'(x) is shown. This is where f(x) has a relative maximum.
What is x = -3 ?

The graph shown is f"(x). This is where f has inflection point(s).
What is x = -3 ?
These are the x values of the inflection points of f.

What is x = 1 ?