If –3 + i is a root of the polynomial function f(x), which of the following must also be a root of f(x)?

a)-3-i
b)-3i
c)3-i
d)3i

we know that

The conjugate root theorem states that if the complex number is a root of a polynomial f(x), then the complex conjugate is also a root of that polynomial.

in this problem we have that

is a root of the polynomial function f(x)

so

the complex conjugate is also a root of the function f(x)

therefore

the answer is the option A

i think it would be 42cm

$4034.40

the perimeter of the field is the sum of the lengths of the four sides:

47 yd + 158 yd + 47 yd + 158 yd = 410 yd

the cost of 3 ft (1 yd) of fence is 3×$3.28 = $9.84.

so the cost of jake's wood perimeter fance is

(410 yd) × ($9.84 /yd) = $4034.40