2014-08-18 09:00:05

If f(x) = -x²  - 3x for all integers, which of the following has the greatest value?

(A) f(-2)
(B) f(-1)
(C) f(0)
(D) f(1)
(E) f(2)

The correct answer is A

Explanation: Simply plug in the answer choices and see which input creates the largest output.

f(-2) = x² – 3x = (-2)² – 3(-2) = (4) – (-6) = 10

f(-1) = x² – 3x = (-1)² – 3(-1) = (1) – (-3) = 4

f(0) = x² – 3x = (0)² – 3(0) = (0) – (0) = 0

f(1) = x² – 3x = (1)² – 3(1) = (1) – (3) = -2

f(2) = x² – 3x = (2)² – 3(2) = (4) – (6) = -2

10 is the largest output, and that comes when the input is -2. Thus, choice A is correct.