Reddit reviews Handbook of Mathematical Functions: with Formulas, Graphs, and Mathematical Tables (Dover Books on Mathematics)
We found 3 Reddit comments about Handbook of Mathematical Functions: with Formulas, Graphs, and Mathematical Tables (Dover Books on Mathematics). Here are the top ones, ranked by their Reddit score.
Before google, the standard reference for applied maths was Abramowitz & Stegun, which weighs in at a thousand pages, and even that doesn't have "most".
I'm afraid to say that there are a lot of formulas in mathematics. Really if you want a formula sheet, you have to restrict yourself to a single topic.
If you want theoretical / mathematical I would suggest reading a few math, stats or engineering books.
Dover is a great place to find some cheaper reading material. They republish old scientific and math texts that were popular in their time in a smaller sized paperback. They're a nice size to bring around with you and they don't cost much.
Math and stats findings of today build on this knowledge, and much of it is still used in state-of-the-art applications. Or, that math/stats is used as part of some state-of-the-art algorithm. Lots of the newest ML algorithms are blending math from a variety of areas.
Statistical analysis of experimental data
Principals of Statistics
Information Theory
Statistics Manual
Some theory of sampling
Numerical Methods for Scientists and Engineers (Hamming)
Mathematical Handbook for Scientists Engineers
Handbook of Mathematical Functions: with Formulas, Graphs, and Mathematical Tables
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There is also the Data-Science Humble Bundle for more technical / practical skill building.