Is the indicated complex number a zero of the polynomial functionf?1 +2i;f(x) =x⁴2x³11x²+32x80

Use the Conjugate Zeros Theorem and other techniques to find all other zeros. (If there are no other zeros, enter NA. Enter your answers as a comma-separated list.)

x=

Give the complete factorization off(x).

f(x) =

Use Descartes's rule of signs to state the number of possible positive and negative real roots. (Enter your answers as a comma-separated list.)x⁴+2x³20x²2x+21= 0

number of possible positive real roots:

number of possible negative real roots: