Reference no: EM132076784

Let f(x)= 7x-4/ x+4. Find the open intervals on which f is concave up (down). Then determine the x-coordinates of all inflection points of f.1.  f is concave up on the intervals 2.  f is concave down on the intervals 3.  The inflection points occur at x = 

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 x values or the word "none".