We use the derivative to determine the maximum and minimum values of particular functions (e.g. cost, strength, amount of material used in a building, profit, loss, etc.). Derivatives are met in many engineering and science problems, especially when modelling the behaviour of moving objects. Derivatives are referred to the situation when a quantity p varies with respect to another quantity q, fulfilling a condition p =f (q), and dp/dq (or f ‘ (q)) represents the change of rate of p with respect to q and dp/dq where q = q0 or f ‘ (q0) represents the rate of change of p with respect to q at q = q0. Chapter 6 defines derivatives, rate of change of quantities, increasing and decreasing functions, tangents and normals, approximations, maxima and minima, first derivative test, maximum and minimum values of a function in a closed interval and miscellaneous examples. Here, students can find the exercises explaining these concepts correctly.