I finally found the cubic vertex formula without calculus!

We know the vertex formula of a parabola y=ax^2+bx+c is at x=-b/(2a), but what if we have a cubic function y=ax^3+bx^2+cx+d? This math tutorial provides a complete guide to finding a cubic curve's local min/max, all with just algebra! The previous video (with a mistake at the end) 👉 https://youtu.be/udcUG2MOUkE The 2017 video 👉 https://youtu.be/3FiLDibOD3s?si=IMJ_pUxET2vT0rdg Support this channel and get more content 👉 https://www.patreon.com/blackpenredpen ---------------------------------------- Big thanks to my Patrons for the full-marathon support! Ben D, Grant S, Mark M, Phillippe S. Michael Z, Jan P. Devun C. Stefan C. Ethan BW Didion S. NN Minkyu Y Brandon F Levon M shortsleeve Jack P Gabriel G Yeeted C David H Mateo F Emma M Eden E Minicat Jose R Nicholas Fey Tyler B Lucas W Ahmet Ö An R Camila L Luupo Farrah Batman 1127 Mathguru Дмитрий П. Michelle L. Alin V. Archer. L Ali. Subotai B. Spencer A. Chris Jason B. Ou S. Nuddi M. Jackson M. Jordan T. Gregorio B. Omkar N. John D. Zero Jeffrey C J D Chaz W. Ryan Turbo S Arcana Rehan M ---------------------------------------- #blackpenredpen #math #mathforfun