Let f(x)=−2 x^3 − 3 x^2 − 2 x − 10. Find the interval where f is concave up. I

Answer: < x <
Find the interval where f is concave down.
Answer: < x <
Find the inflection point of f. Answer: x=

take the second derivative f '' (x)

if f '' (x) is positive, the graph is concave upwards
if f '' (x) is negaive , the graph is concave downwards
if f '' (x) = 0, you have a point of inflection

should be easy to do, since f '' (x) is first degree.