Evaluate each definite integral. 12(x2 -1)2dx 13. So 1+x3 dx Find the area of the region under the graph of the function fon the interval given. Make sure to sketch its graph. f ( x ) = - In x x -; [1, 4] Sketch the graphs of the functions f and g, and find the area of the region enclosed by these graphs and the vertical lines x = a and x = b. f(x) = 9 - x2, g(x) = 2x +3;a=-1,b =1