In the xy-plane, the parabola with equation y=x2+2 intersects the line x−y=−4 at two points. What is the sum of the x-coordinates of the two points of intersection? -1

1

2

5

The coverage of a base station of a telecommunication company forms a disk with a radius of (kilometers). let be the distance of a cellphone from a base station. assume that the location of cellphones in use are randomly uniformly distributed within the disk. calculate the mean and variance for the random variable.