👉 Penny-formula is a mathematical concept that defines a function where the output of the function depends on the input. The formula for penny-formulas can be written as: f(x) = 1/2x^2 where x is the input value and f(x) is the output value. For example, if we have a function called "y" that outputs 5 when its input is 3, then y(3) would equal 5. Similarly, if we have