Letf(x)= x^(4) 7x^(3) + 4x + 1.

Find the open intervals on whichf is concave up (down). Then determine the x-coordinates of all inflection points off.

1.fis concave up on the intervals

2.fis concave down on the intervals

3.The inflection points occur atx=

Notes:In the first two, the answers 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, the answer should be a comma separated list ofxvalues or the word "none".