If f(x) = x² − 2x + 4, what is f(−3)?

Think it through first, then pick an option.

Answer and explanation

Correct answer: a 19

f(−3) = (−3)² − 2(−3) + 4 = 9 + 6 + 4 = 19.

Why the other options are wrong

b 16: 9 + 6 = 15 and then + 4 gives 19, not 16.
c 4: This is just the constant term; the value of x has to be put in.
d 1: −2(−3) = +6; taking −6 would give 9 − 6 + 4 = 7. The value 1 does not come from a correct step.