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Integration techniques

Definite integrals and the fundamental theorem

Material by the IntegralPaso project. Conditions and limits are stated in each guide; external teaching review is pending.

∫abf(x) dx=F(b)−F(a)\int_a^bf(x)\,dx=F(b)-F(a)

Find a primitive and evaluate upper minus lower endpoint. This evaluation requires the theorem conditions; singularities require improper integrals. Transform bounds under substitution.

Common mistake

Do not cross a singularity using F(b)−F(a) without checking convergence.

Step-by-step example

  1. Find a primitive.

    ∫02x2 dx,F(x)=x3/3\int_0^2x^2\,dx,\quad F(x)=x^3/3
  2. Evaluate both endpoints.

    F(2)−F(0)=8/3−0F(2)-F(0)=8/3-0
  3. The definite result has no C.

    I=8/3I=8/3
Solve