Final answer:
A quadratic function with a leading coefficient of 3 and a constant term of -12 is f(x) = 3x^2 - 12.
Step-by-step explanation:
A quadratic function has the form f(x) = ax^2 + bx + c, where a is the leading coefficient, b is the coefficient of the linear term, and c is the constant term. In this case, the quadratic function with a leading coefficient of 3 and a constant term of -12 is:
f(x) = 3x^2 + 0x - 12
So, the correct answer is f(x) = 3x^2 - 12.