Hello, ^_^Engineer_Adam^_^!
Plot the graph of the function and from the graph, estimate the point of inflection
and where the graph is concave upward and concave downward.
Confirm your estimates analytically.
. . I used an "eyeball" approach to graph it.
We have: .
This is a "sideways" cubic with its vertex at (2,0). Code:

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        *   +      
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It appears that it is concave up for and concave down for .
We have: .
Then: .
At is undefined.
For . concave up:
For . concave down:
Therefore: .