What are the points of inflection, if any, of #f(x) = x^5/20 - 5x^3 + 5 #?
The points of inflection are
Points of inflection are where the second derivative of a function is equal to 0, and where the second derivative of a function switches signs. So first you find the second derivative and set it equal to 0.
Factor out the x.
To check if these are all inflection points, you check if the signs change around them. I plugged in