how to write the characteristics polynominal-matlab

hi,

this is the equation I was able to write in Matlab

AF = (z-z1)*(z-z2)*(z-z3) -------------- (1)

where I calculated the values of z1, z2 and z3 using my program

as z1 = j, z2 = 1 and z3 = -j .-----------(2)

from this I have to form the equation in the following format as

AF = z^3-z^2+z-1 -------------(3)

and to write the coefficients of the equation as

a1 = -1 ,a2 = 1, a3 = -1 and a4 = 1 ----------(4)


can anybody help me how to proceed further
to form equation (3) and (4) in matlab

thanx for those give a try. but i got it myself