Answer
a) Increasing/Decreasing Test
b) Concavity Test
c) See where concavity changes/Set second derivative to 0
Work Step by Step
a) To see where a function is increasing or decreasing, we use the Increasing/Decreasing Test, which states that if $f'(x)\gt0$ then the function $f(x)$ is increasing and that if $f'(x)\lt0$, the function $f(x)$ is decreasing.
b) To see where a function is concave up or down, we use the Concavity Test. This states that if $f''(x)\gt0$, then the function $f(x)$ is concave up and if $f''(x)\lt0$, then the function $f(x)$ is concave down.
c) Inflection points are when the concavity of a graph changes. So, to locate these points, simply find the x and corresponding y values of where the concavity changes from concave up to down or vice versa. An additional way to find inflection points is to solve for x when the second derivative is set to 0.
