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### Episode 04a (30:07): Basic matrix wrangling & the dangers of multiplication

#### Summary:

We get back to basics with a howto session on matrix operations starting with scalar multiplication and addition. We then take a look at multiplication starting with the fundamental inner product definition. Matrices do many things like normal numbers but multiplication is the big exception: We see why almost always $BA \ne AB$, even if both products are defined. Next: Advanced Wrangling.