Find approximations to within 10−5 to all the zeros of each of the following polynomials by first finding the real zeros using Newton's method and then reducing to polynomials of lower degree to determine any complex zeros.
a. f (x) = x4 + 5x3 − 9x2 − 85x − 136
b. f (x) = x4 − 2x3 − 12x2 + 16x − 40
c. f (x) = x4 + x3 + 3x2 + 2x + 2
d. f (x) = x5 + 11x4 − 21x3 − 10x2 − 21x − 5
e. f (x) = 16x4 + 88x3 + 159x2 + 76x − 240
f. f (x) = x4 − 4x2 − 3x + 5
g. f (x) = x4 − 2x3 − 4x2 + 4x + 4
h. f (x) = x3 − 7x2 + 14x - 6