A Retrospect to Begin with... In calculus, the concepts of limits and continuity form the foundation upon which differentiability is built. A limit helps us understand the behavior of a function as it approaches a specific point, while continuity ensures that a function has no abrupt jumps or breaks. Differentiability takes these ideas further, exploring how a function changes at an infinitesimal level. What is Differentiability? Differentiability is essentially defined as the ability to derive the function. A derivative refers to the slope of the tangent line to a curve defined at a point on the curve, or alternatively, it can define the function's instantaneous rate of change. To understand this better, consider the car analogy . If you travel 100 kilometers within 2 hours, the average speed can be calculated as 50 km per hour. Nevertheless, this does not tell whether the car was going really fast or with less speed or was really slow. The derivative describes this aspect by show...