Integration Explorer

Visualize definite integrals as shaded area, explore the Fundamental Theorem of Calculus, and compute area between two curves.

Integration

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The Math Behind It

Definite Integrals

  • Defined as the limit of Riemann sums: ab f(x)dx = limn→∞ ∑ f(xi)Δx
  • Notation: ab f(x)dx where a is the lower limit and b is the upper limit
  • Geometric meaning: the signed area between f(x) and the x-axis from a to b
  • Area above the x-axis is positive; area below is negative
  • Properties: linearity, additivity over intervals, comparison

Fundamental Theorem of Calculus

  • FTC Part 1: d/dx ∫ax f(t)dt = f(x) — differentiation undoes integration
  • FTC Part 2: ab f(x)dx = F(b) − F(a) where F is any antiderivative of f
  • Connects the two central operations of calculus: differentiation and integration
  • Area between curves: ab |f(x) − g(x)|dx
  • When f(x) ≥ g(x) on [a, b], the absolute value can be dropped