Help with this math question, I am graphing them to see which one is correct, but please help so I can speedy out of this, please?

Answer:
Last one: 3x²
Step-by-step explanation:
Quadratics are functions with the power of 2 as the highest.
Option 1 is a Reciprocal function
Option 2 is a linear function
Option 3 is a exponential function
Option 4 is a quadratic function