A quadratic function is any function whose highest exponent, or power, is 2. The highest exponent on f(x) is 2. For g(x) it is 3. For k(x) it is 1 and for b(x) it is 4.
Thus f(x) is a quadratic, and choice A is best.
f(x)=5x^2-4x+5
Step-by-step explanation:
