3. When tangent slopes are increasing the graph of f is concave up
When tangent slopes are decreasing the graph of f is concave
down
f ' is increasing
f ' is decreasing
Inflection
point
Inflection point = where the direction of concavity changes.
Note: Sign of f '' changes at this point
To find inflection points find where f'' is zero or undefined.
HOWEVER, not all points will be inflection points.
Must check that f'' as opposite signs on either side of point.
4.
5. Ex. Find the inflection points of f(x) = x4 +2x3 - 1
