I need to find the points on inflection and discuss the concavity of the graph of the function:
I know that points of inflection require setting the second derivative equal to zero and finding where it is undefined.
Here is my work so far...
f''(x)= -1/4x^(-3/2) +3/4x^(-5/2)
My problem is that when I find the zeros of f''(x) I get x=3. That makes sense. But when I see where it is undefined, it is undefined from (-infinity,0).
How can I use this information to find points of inflection and where the graph is concave up/down?
Thanks so much!!!