Let f(x) denote the function graphed. Estimate where f(x)(a) has local minima(b) has local maxima(c) has inflection points(d) is increasing(e) is decreasing(f) is concave up(g) is concave down

We must find some properties of the function f(x) plotted in the graph.
(a) Local minima
We see that the function has a local minimum at the point (0,0).
(b) Local maxima
We see that the function has a local maximum at the point (-2,4).
(c) Inflection points
By definition, an inflexion point of a curve is a point at which a change in the direction of curvature occurs.
We see that in the interval (-2, -1) the slope of the curve decreases, but at the point (-1, 2) we have a change of the curvature and the slope starts to increase. So (-1, 2) is an inflexion point.
(d) Is increasing
The function is increasing when the slope of a tangent line to the curve is positive.
We see that the function has a tangent line with a positive slope on the intervals:
• (-∞, -2),
,• (0, ∞).
So the function is increasing in the interval (-∞, -2) U (0, ∞).
(e) Is decreasing
The function is increasing when the slope of a tangent line to the curve is negative.
We see that the function has a tangent line with a negative slope on the intervals:
• (-2, 0).
So the function is increasing in the interval (-2, 0).
(f) Concave up
The curve is concave up in the zones with a U shape.
So the curve is concave up in the interval (-1, ∞).
(g) Concave down
The curve is concave down in the zones with a ∩ shape.
So the curve is concave down in the interval (-∞, -1).
Answers
(a) Point (0, 0)
(b) Point (-2, 4)
(c) Point (-1, 2)
(d) Interval (-∞, -2) U (0, ∞)
(e) Interval (-2, 0)
(f) Interval (-1, ∞)
(g) Interval (-∞, -1)