Differentiation in N(A)-Level Additional Mathematics (4051): the derivative as a gradient, the power, chain, product and quotient rules, tangents and normals, and stationary points and their nature

An N(A)-Level Additional Mathematics (4051) overview of differentiation in the Calculus strand. How the derivative as a gradient leads to the power, chain, product and quotient rules, then to tangents and normals, and to stationary points and deciding their nature, with links to every dot point.