Which of the following sets is the range of the function f(x)=3+(x2−5x+6x2+5x−6)2f(x)=3+\left(\dfrac{x^2-5x+6}{x^2+5x-6}\right)^2f(x)=3+(x2+5x−6x2−5x+6)2 ?
Squared values cannot be negative, so the minimum value of f(x)f(x)f(x) is 3. All of the answer choices show minimum values lower than 333, which is not possible.