Which represents a quadratic function? f(x) = −8x3 − 16x2 − 4x f (x) = x 2 + 2x − 5 f(x) = + 1 f(x) = 0x2 − 9x + 7

The correct answer is

Step-by-step explanation:

A Quadratic equation is defined as the equation in which the highest power of the variable is 2. The general form of this equation represents:

where,

From the given options:

1. : Here, the highest power of the variable is 3. Therefore, it is not a quadratic equation.

2. : Here, the highest power of the variable is 2. Therefore, it is a quadratic equation.

3. : Here, the highest power of the variable is 0. Therefore, it is not a quadratic equation.

4. : Here, the highest power of the variable is 1. Therefore, it is not a quadratic equation.

Hence, the correct answer is