What a derivative actually is

After this lesson you can: Read a derivative as a slope, which is all gradient descent needs.

Watch

• The paradox of the derivative | Chapter 2, Essence of calculus - 3Blue1Brown, 17 min. Directly targets the derivative intuition a beginner needs: instantaneous slope rather than symbolic manipulation.
• The essence of calculus - 3Blue1Brown, 17 min. A short visual entry point from a trusted channel for rebuilding calculus intuition from zero.
• Derivative formulas through geometry | Chapter 3, Essence of calculus - 3Blue1Brown, 18 min. Useful follow-up connecting derivative rules to geometry, while keeping the focus visual rather than algebraic.

Notes

A derivative is a way to describe how fast one quantity changes when another quantity changes. On a graph, it is the slope of the curve at a point. If the line is steep upward, the derivative is positive and large. If it is flat, the derivative is near zero. If it slopes downward, the derivative is negative. For gradient descent, that picture is the important part: the derivative tells you which direction changes the value and how strongly.

Unlock the full lesson notes, the exercises and the graded checkpoint - ₹5,000 once.