In short, mostly you only need to use codeforces (no matter what contest you're training for), find a rating range where you can solve around ~30-40% of the time on your own, and just grind down the problem set tab in reverse order of id (the default sorting). Also take part in...
In summary, to find the intervals where the function is increasing and decreasing, you would need to find the first derivative and then solve the resulting 3rd order equation. This can be done by creating a sign chart of the first derivative and finding the critical points. One of th...
She also noticed that the student was misreading the graph, and that they were actually identifying where the function f had a maximum when they “pinpoint[ed] … it changes from positive to negative.” Further, Ida recognized that when the student said “changing concavity” they were ...
For a point to be the point of inflection, it has to both switch convexity/concavity and change signs on the second derivative.[2] To find the inflection point on a graph, look for the point where the function switches concavity. On the graph above, it’s the middle point where the ...