Approximate ∫ f(x) dx for integrals with infinite limits or singularities at endpoints using the trapezoid rule.
Trapezoid rule approximation for ∫ f(x) dx:
$$\int_a^b f(x) dx \approx \frac{h}{2} \Big[f(a) + 2 \sum_{i=1}^{n-1} f(x_i) + f(b)\Big], \quad h = \frac{b-a}{n}$$