A function is described as a quadratic function if the highest power of the variables of the function is 2.
For
The highest power of x is 1, hence, the function is not a quadratic function.
For
The highest power of a is 2, hence, the function is a quadratic function.
For
The highest power of y is 1, hence, the function is not a quadratic function.
For
The highest power of b is 2, hence, the function is a quadratic function.
Therefore, the quadratic functions are (4a + 2)(2a - 1) + 1 = 0 and <span>2b(b - 7) + b = 0</span>