In: Math
a) Let f(x) = −x^4 − 4x^3 . (i) Find the intervals of increase/decrease of f. (ii) Find the local extrema of f (values and locations). (iii) Determine the intervals of concavity. (iv) Find the location of the inflection points of f. (v) Sketch the graph of f. (You can choose your own scale for the graph)
b) A farmer wants to fence in an area of 6 km2 in a rectangular field and then divide it in half with a fence parallel to one of the sides of the rectangle. Find the dimensions of the rectangular field that minimize the amount of fence used.
Express the area of the region bounded by the graph of f(x) = 2 + √ x and the x-axis in the interval [3, 8] as a limit of sums using right endpoints. Do not evaluate the limit.