1, 3
-1, -3
1, -3
-1, 3
Correct answer is A
\(f(x) = 3x^{2} - 12x + 12\) and \(f(x) = 3\)
\(\therefore f(x) = 3 = 3x^{2} - 12x + 12 \implies 3x^{2} - 12x + 12 - 3 = 0\)
\(3x^{2} - 12x + 9 = 0; 3x^{2} - 9x - 3x + 9 = 0\)
\(3x(x - 3) - 3(x - 3) = (3x - 3)(x - 3) = 0\)
3x - 3 = 0 or x - 3 = 0
\(x = 1 or 3\)