3.2 Electrical applications -- 3.3 Stationary points -- 3.4 Small changes -- Further problems -- 4 Numerical differentiation -- 4.1 Derivatives from discrete values -- 4.2 Two-point equation -- 4.3 Three-point equation -- 4.4 Five-point equation -- 4.5 Commonly used approximations -- Further problems -- 5 Introducing integration -- 5.1 The concept of integration -- 5.2 Integrals of common functions -- 5.3 Integral equations -- Further problems -- 6 Techniques of integration -- 6.1 Basic rules -- 6.2 Integration by substitution -- 6.3 Integration by parts -- 6.4 Integration by partial fractions