Carcass wrote:
If f(–0.5)=0, which of the following could be f(x)?
(A) 2x+2
(B) 4x–2
(C) 4x2–1
(D) x2–1
(E) (–x)2–2.5
With function problems and variables in the choices, plugging in values is the most efficient tactic.
In this case, plug (-0.5) into each choice to see if it = 0 to meet the conditions of the problem:
(A) 2(-0.5) + 2 ≠ 0 | Eliminate
(B) 4(-0.5) + 4 ≠ 0 | Eliminate
(C) 4(-0.5)² + 1 = 0 | Keep
(D) (-0.5)² + 1 ≠ 0 | Eliminate
(E) (0.5)² -2.5 ≠ 0 | Eliminate
Only one choice matches the conditions of the problem, so select Choice C.