**References:**

Sources/Further Reading:

- http://mathonline.wikidot.com/the-norm-of-a-vector
- https://www.math.ucdavis.edu/~hunter/book/ch1.pdf
- https://ncatlab.org/nlab/show/Banach+algebra
- http://individual.utoronto.ca/jordanbell/notes/wieneralgebra.pdf
- https://brilliant.org/wiki/fourier-series/

Images: