Page 111 from a differential calculus textbook, showing equations and a diagram of tangents to a convex curve, with handwritten annotations.
A page from a textbook on differential calculus, featuring mathematical equations and a diagram illustrating tangents to a convex curve. The page includes formulas for PT, PR, MT, and MR, with a specific case for a parabola (n = 0). A handwritten note "See margin" is present, along with a figure showing points and tangents on a coordinate system.