Calculus

Author

Chao Ma

Published

February 8, 2026

Notes

Short, structured notes on calculus fundamentals, focused on change, accumulation, and geometric intuition.


Gilbert Strang’s Calculus: Power Series and Euler’s Great Formula Build Taylor series from derivatives at zero, derive the series for \(e^x\), \(\sin x\), and \(\cos x\), then combine them into Euler’s formula and the geometric/logarithmic series.

Gilbert Strang’s Calculus: Linear Approximation and Newton’s Method Use tangent-line linearization to approximate nearby values, then turn the same idea into Newton’s root-finding iteration, with examples from \(\sqrt{9.06}\) and \(e^{0.01}\).

Gilbert Strang’s Calculus: Growth Rates and Log Graphs Compare linear, polynomial, exponential, factorial, and logarithmic growth, then use log scales and log-log plots to reveal power laws and numerical error rates.

Gilbert Strang’s Calculus: Derivatives of ln y and arcsin(y) Use inverse functions and the chain rule to derive \(\frac{d}{dy}(\ln y)=\frac{1}{y}\) and \(\frac{d}{dy}(\arcsin y)=\frac{1}{\sqrt{1-y^2}}\), with the logarithm filling the missing \(y^{-1}\) power.

Gilbert Strang’s Calculus: Limits and Continuous Functions Formal \(\epsilon\)-\(N\) and \(\epsilon\)-\(\delta\) definitions, indeterminate forms, a \(1^\infty\) limit example, L’Hopital’s rule, and the core link between limits and continuity.

Gilbert Strang’s Calculus: Chains and the Chain Rule Chain rule for composite functions with clean examples, intuition from delta-ratio decomposition, and Gaussian first/second derivatives via chain + product rules.

Gilbert Strang’s Calculus: Product Rule and Quotient Rule From rectangle-area increments to formula derivation: product rule, quotient rule, chain-like power patterns for f(x)^n, and worked checks with sqrt(x) and 1/x^n.

Gilbert Strang’s Calculus: Derivative of sin x and cos x A geometric-and-limit proof of \(\frac{d}{dx}(\sin x)=\cos x\) and \(\frac{d}{dx}(\cos x)=-\sin x\), including the key limit \(\lim_{h\to0}\frac{\cos h-1}{h}=0\).

Gilbert Strang’s Calculus: Big Picture Integral Connect derivatives and integrals through sums, differences, and area accumulation; then verify with a worked example from slope to distance.

Gilbert Strang’s Calculus: The Exponential Function Build \(e^x\) from the condition \(y'=y\), derive the factorial series coefficients, and connect the limit \((1+1/N)^N\) to continuous compounding.

Gilbert Strang’s Calculus: Max, Min, and Second Derivative Use first and second derivatives to classify extrema and find inflection points, with worked examples from \(\sin x\) and a cubic.

Gilbert Strang’s Calculus: Big Picture on Derivatives A compact map of derivatives through slopes, limits, and the core function families: power, trigonometric, and exponential.

Gilbert Strang’s Calculus: Highlights A concise tour of derivatives, slopes, second derivatives, exponential growth, extrema, and the integral as accumulation, guided by graphs and intuition.