Analytically determine a) the extrema of f(x) = 5x3 b) the intervals on which the function is increasing or decreasing c) intervals where the graph is concave up & concave down 6. Use the Second Derivative Test to find the local extrema for f(x) = -2x³ + 9x² + 12x 7. Find: a) all points of inflection of the function f(x)=√x + 2 b) intervals on which f is concave up and concave down.