envelope theorem | Optimal value Function | indirect objective Function |  

in this video we will learn about envelope theorem.
The envelope theorem is a mathematical result in economics that describes the relationship between changes in a function and changes in one of its arguments. The theorem states that the effect of a small change in an argument on the value of a function can be approximated by the derivative of the function with respect to that argument, evaluated at the current value of the argument. The theorem is often used to analyze the properties of optimization problems and can be applied in a wide range of fields including finance, microeconomics, and public policy.