Given the function f(x)=(-3x+6)e^(-x)Determine where the function is increasing and where it is decreasing.Determine where the graph of the function f is concave up and where it is concave down.Find relative extremum of the function f(x).Find absolute extremum of the function f(x) on 1,4People want to build a house model with a semi-cylindrical shape, radius r, height r placedon 4 rectangular walls of height h as shown. People only have 100\pi ^(*)f_(0)_(m)^(2) of plasticmaterial to make this model. Determine the value of r so that the house has the largestvolume.