If I had a graph of f', would the intervals where f' is decreasing be the same as the intervals where f is decreasing? For example, the graph of f' is degreasing from -1 to 0. Is f decreasing from -1 to 0 also? With the same graph of f', how would you know on which intervals f is concave up or down? Would I need to find f'' and how would I do that with just the graph? Same thing with the inflection points, would I need f''? If I didn't have a graph, just the equation of f', would I find the intervals of increasing and degreasing by finding what numbers make f' = 0, and check wether those numbers if put back into the equation come out postive or negative?