Question

MEDAL & FAN ANYBODY ?
A quadratic function f(x) has two complex roots: x = 3 – i and x = 3 + i. Which one of the following is the correct expression for f(x)?
a. f(x) = x2 + 9
b. f(x) = x2 – 6x + 10
c. f(x) = x2 – 6x + 9
d. f(x) = x2 – 6x – 9

Answer 1

if x=3-i then x-(3-i) is a factor
if x=3+i then x-(3+i) is a factor
I multiply (x-(3-i))(x-(3+i))

Answer 2

Is it D? @freckles

Answer 3

we can multiply the above to find out

Answer 4

have you tried that

Answer 5

Its b

Answer 6

\[(x-(3-i))(x-(3+i)) \\ x \cdot x+x \cdot -(3+i)-(3-i) \cdot x +(3-i)(3+i)\]
yes that sounds a lot better :)