A functionf:R{−2,2}→Ris defined byf(x) =x3+ 2xx2−4.(a) Find all critical points off.(b) Use the first derivate test to determine whether each of the critical points is a relative maximum,relative minimum, or neither.(c) Find all points of inflection, and determine on which regions ofRfis concave up, and on whichregionsfis concave down.(d) Use the above information to sketch a graph off.