Tag: dy/dx

Leibniz changed mathematics with dy/dx and the integral sign, making the calculus of change clear and graspable. Medicine did something similar with vivid radiological mnemonics — the “rat’s tail” of carcinoma oesophagus, the “apple core” of colonic cancer, the “bird’s beak” of achalasia, the “string sign” of Crohn’s disease. In a ward-round vignette, Dr. Pradeep…