Finding critical point, inc/dec, inflection point and CU/CD of a function

http://www.webassign.net/cgi-bin/sym...28x%5E2%2B3%29

So far I did this:

Critical Point : 0
Increasing : (0,INFINITY)
Decreasing : (-INFINITY,0)
Local Maximum: 1/4
Local Minimum: 0

Inflection Points: x = 1, x = -1
Concave Up: (-1,INFINITY)
Concave Down : (-INFINITY,1)

I cannot able to find CU and CD and local maximum correctly.

Plz help me