Quick Recap — Definite Integrals

  • Fundamental theorem: ∫abf(x) dx=F(b)−F(a)\displaystyle\int_a^b f(x)\,dx=F(b)-F(a) where F′=fF'=f.
  • ∫aaf=0\displaystyle\int_a^a f=0 and ∫abf=−∫baf\displaystyle\int_a^b f=-\int_b^a f.
  • Symmetry: ∫−aa(odd)=0\displaystyle\int_{-a}^{a}(\text{odd})=0 and ∫−aa(even)=2∫0a\displaystyle\int_{-a}^{a}(\text{even})=2\int_0^a.
  • Definite integral gives net signed area.