the.com/leibniz calculus notation
the dy/dx guy won, and now every student thanks a german lawyer for their nightmares.
means the system of writing derivatives as dy/dx and integrals with the elongated s symbol, treating infinitesimal change as if it were a fraction you can manipulate.
from gottfried leibniz developed it in the 1670s alongside newton's independent invention of calculus, sparking a bitter priority feud, but leibniz's notation was so much more usable it simply outcompeted newton's dot notation over the following century.
the integral signis literally a stretched letter s, for summa
newton's rival notationused dots over letters, nearly unreadable now
chain rule tricknotation lets you cancel dy's like fractions, sort of
still standardtaught unchanged in classrooms 350 years later
for instance
differential equations — physics and engineering still write them leibniz's way