2nd derivative is corrected. Any hints on other errors?

Find Critical Points:

- root of is

What is the maximum and minimum?

Where is the interval increasing or decreasing?

For

Negative so decreasing

For

Positive so increasing

What is the inflection point?

Inflection Point

Where is the curve concave up, or concave down?

For

Negative so concave up

For

Positive so concave up