Question

Which function has a vertex at (2, –9)? f(x) = –(x – 3)2 f(x) = (x + 8)2 f(x) = (x – 5)(x + 1) f(x) = –(x – 1)(x – 5)

Answer 1

Answer is F(x)=(x-5)(x+1)

How? Plugged the functions into a graphing calculator until I found the correct vertex that is assuming the 2s were exponents on question a and b.