A piece of wire is bent so that the wire forms a closed circle of radius 3 cm. The density of the wire varies. The density is given by p(x, y) = x g/cm. That means the density only depends on how far left/right a certain point on the wire-circle is. It does not depend on how far up/below the point is. For example, the density at the "eastern" point of the wire-circle is the same as the density at the "western" point of the wire-circle (since x is the same at both these points). It also means that the density at the "northern" point of the wire-circle is zero (since we have x = : 0 at that point). The same is true for the "southern" point of the wire-circle (since we also have x = O there). Calculate the total mass of this circular piece of wire. To do so, you will need to start with a Riemann Sum and then proceed from there. Eventually you should arrive at the exact number: Answer: 6.0 g