For what values of x is the graph of y equals negative 3 divided by the quantity 4 plus x concave downward?

We are given our function as

For finding concavity , firstly we will find second derivative

now, we can find derivative again

now, we can know second derivative is undefined when denominator =0

so, we set denominator =0

and then we can solve for x

now, we can draw a number line and locate x=-4

and then we can find sign of second derivative on each intervals

so,

Concave downward interval:

sorry, i can't understand your question. will later if you describe more clearly!

: )