I am to determine the inflection point and intervals where the graph is concave up and concave down, and I have gotten a wrong answer somehow. I'm guessing it's probably when I solved for y'', it was a very long derivative to simplify:
I was able to find the inflection point but still having some difficulties with the concavity.
The simplified second derivative is
Here's the inequalities I determined:
For it to be concave up,
When I solved these I had
For it to be concave down,
And the solution for this one didn't work out at all.