The quadratic function "f(x) = ax2 + bx + c" is the standard form for quadratic equations. F(x) is representative of the output, and x is the variable, also called the unknown. A, b and c in the equation are known values.
The "a" in the equation can not take on the value of 0 because it would eliminate "x2," which is responsible for making the equation quadratic. The "f(x)" allows it to be called a function. "F" in "f(x)" is the function name, and "x" in "f(x)" is the input. The value of the "x" variable is found by using the quadratic formula. The name quadratic is derived from the word "quad," which means square, and is so called because the variable "x" is squared.