Calculus,
IntuitivelyThe ideas behind Calc 1–3, built from pictures and plain words — for anyone who never liked math.
  • •Preface
I · Limits and Continuity
  • 1What Calculus Is Really About
  • 2Functions, Graphs, and Just Enough Algebra
  • 3The Limit: Getting Arbitrarily Close
  • 4Continuity and Its Breaks
II · Derivatives
  • 5The Derivative
  • 6Rules for Finding Derivatives
  • 7The Chain Rule
  • 8Using Derivatives: Optimization and Change
III · Integrals
  • 9The Integral: Adding Up Infinitely Many Slices
  • 10The Fundamental Theorem of Calculus
  • 11Techniques of Integration
  • 12Using Integrals: Area, Volume, and Accumulation
IV · Sequences and Series
  • 13Sequences: Lists That Go Somewhere
  • 14Series: Adding Infinitely Many Terms
  • 15Power Series
  • 16Taylor Series: Functions as Infinite Polynomials
V · Multivariable Calculus
  • 17Functions of Several Variables
  • 18Partial Derivatives
  • 19Gradients and Optimization
  • 20Multiple Integrals
VI · Vector Calculus
  • 21Vector Fields
  • 22Line Integrals and Flow
  • 23Green's, Stokes', and the Divergence Theorem
Appendices
  • AA Precalculus Survival Kit
  • BGlossary
Chapter 9

9The Integral: Adding Up Infinitely Many Slices

Draft pending — this page is an outline of planned content. Write it by creating content/the-integral.md.

9.1Area as a sum

Planned: Approximating with rectangles, then letting them get thin.

9.2The definite integral

Planned: The limit of those sums, and what it measures.

PreviousUsing Derivatives: Optimization and Change NextThe Fundamental Theorem of Calculus
On this page
9.1 Area as a sum 9.2 The definite integral