When a particle is located a distance meters from the origin, a force of cos (x/3) newtons

When a particle is located a distance meters from the origin, a force of cos (πx/3) newtons acts on it, how much work is done in moving the particle from x = 1 to x = 2? Interpret your answer by considering the work done from x = 1 to x = 1.5 and from x = 1.5 to x = 2.