Question 593317
complex roots (containing i) occur in conjugate pairs ___ if 2-i is a root, 2+i is also


if r is a root, then z-r is a factor


the product of factors is a factor ___ (z - 2 + i)(z - 2 - i) = z^2 - 4z + 5


to get a coefficient of 2 for z^3 and a -5 for the constant term, the 3rd factor must be 2z-1


(2z - 1)(z^2 - 4z + 5) = 2z^3 - 8z^2 + 10z - z^2 + 4z - 5 = 2z^3 - 9z^2 + 14z - 5