The position of an aircraft relative to an observer on the ground is estimated by measur...

The position of an aircraft relative to an observer on the ground is estimated by measuring its distance r from the observer and the angle θ that the line of sight from the observer to the aircraft makes with the horizontal. Suppose that the measurements, denoted by R and

a. Find an approximate expression for the variance of Y .

b. For given r, at what value of θ is the estimated altitude most variable?