(a) If x is the your distance from the wall holding the painting, find a function A(x) that computes the angle a in the picture; A(x)= arctan( 13 x)−arctan( 3 x) (b) Find the rate of change with respect to x of the angle a when you are at the location x (c) Find the rate of change with respect to x of the angle a when you are at the location x=4 m. (Exact answer.) (d) Find the rate of change with respect to x of the angle a when you are at the location x=13 m. (Exact answer.) (e) Find the location where the rate of change with respect to x of the angle a is zero m.(Exact answer.) (f) When you are standing at the location to maximize a, what is the value of a