It’s not joke, it’s rigorous enough for physics… 😂

Learn more math with Brilliant, click https://brilliant.org/blackpenredpen/ and get 20% off your annual premium subscription. Let y=f(u) and u=g(x).We know that dy/dx = dy/du * du/dx by the chain rule. However, what if we had d^2y/dx^2? #calculus 🛍 Shop my math t-shirt & hoodies: https://amzn.to/3qBeuw6 👉 Support this channel and get more content   / blackpenredpen   ----------------------------------------