Answer:
Quadratic Function
Explanation:
f(x) is a quadratic function because when distributed you get:
. A quadratic function is a polynomial with a degree (power) of two or more.
The other options are eliminated because:
A linear function has a variable with a power of 1 or no variable at all.
A square-root function has a leading variable with a power of 1/2.
An exponential function has a term to the power of a variable.