Calculus/Integration techniques

Various techniques for evaluating integrals are below.

4.5 Infinite Sums 4.6 Derivative Rules and the Substitution Rule 4.7 Integration by Parts 4.8 Trigonometric Substitutions 4.9 Trigonometric Integrals 4.10 Rational Functions by Partial Fraction Decomposition 4.11 Tangent Half Angle Substitution 4.12 Reduction Formula 4.13 Irrational Functions 4.14 Numerical Approximations