Let [math]. Find the open intervals on which [math] is concave up (down). Then determine the [math]-coordinates of all inflection points of [math].

1.  [math] is concave up on the intervals
2.  [math] is concave down on the intervals
3.  The inflection points occur at [math] =

Notes: In the first two, your answer should either be a single interval, such as (0,1), a comma separated list of intervals, such as (-inf, 2), (3,4), or the word "none".

In the last one, your answer should be a comma separated list of [math] values or the word "none".