This block contains units 21 - 24Unit 21 Fourier SeriesThis unit is concerned with the technique of expressing a periodic function as a sum of terms, where each term is a constant, a sine function or a cosine function. This unit assumes you have a background knowledge of the definition of the period (unit 7), forced oscillations and resonance (Unit 17, and integration by parts (Unit 1).Unit 22 Partial Differential EquationsThis unit builds on ideas previously introduced in unit 12 regarding The diffusion equation and the wave equation, in the context of modelling the vibrations of a taut string (such as guitar string).Unit 23 Scalar and Vector FieldsThe main focus of this unit is the differential calculus of scalar and vector fields, i.e. the study of how scalar and vector fields vary from one point to another. A brief introduction to the properties of orthogonal matrices and pictorial representations of scalar and vector fields is given along with an extended discussion of the gradient function of a scalar field. Cylindrical and spherical polar coordinate systems for specifying points in three dimensions is also introduced in this unit.Unit 24 Vector CalculusThis unit discusses the divergence of a vector field, the curl of a vector field, the scalar line integral and linking line integrals curl and gradient. This unit also builds on the concepts of kinetic energy and potential energy.

尊敬的读者：
欢迎您访问我们的网站。本站的初衷是为大家提供一个共享学习资料、交换知识的平台。每位用户都可以将文件上传至网盘并分享。
然而，随着用户上传的资料增多，我们发现部分不宜或版权问题的书籍被分享到了本站。
为此，我们已经关闭了分享入口，并进行了多次书籍审查，但仍有部分内容未能彻底审查到位。
在此，我们恳请广大读者与我们共同监督，如发现任何不宜内容，请 点击此处 进行举报，我们会第一时间处理并下架相关内容。
希望我们能共建一个文明社区！感谢您的理解与支持！