Posted by **Ethan** on Tuesday, September 27, 2011 at 11:55pm.

given the graph of f(x) = x sinx, 0<=x<=2pi

assuming that a quantity y changes at a rate of y' = xsinx, find by how much it will increase or decrease over 3pi/2 <= x <= 2pi

the area under the graph from 0 to pi/2 is 1

the area under the graph from pi/2 to pi is pi-1

the area under the graph from pi to 3pi/2 is pi+1

and the area under the graph from 3pi/2 to 2pi is 2pi-1