The discussion revolves around the concept of determining the gradient of an unknown function without traditional differentiation methods. Mubashir proposes a trigonometric approach involving secant lines and angles, claiming it can yield accurate approximations for derivatives. However, other participants highlight flaws in his reasoning, emphasizing that averaging secant slopes is a more straightforward and precise method for quadratic functions. They argue that differentiation is an exact process, while Mubashir's technique relies on approximations that can vary in accuracy depending on the function and point chosen. The conversation underscores the importance of understanding limits and the definition of derivatives in calculus.