4: Least Squares
- Page ID
- 21825
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- 4.1: Least Squares
- We learned in the previous chapter that Ax=b need not possess a solution when the number of rows of A exceeds its rank, i.e., r<m. As this situation arises quite often in practice, typically in the guise of 'more equations than unknowns,' we establish a rationale for the absurdity Ax=b.
Thumbnail: What is the best fit? (CC BY-SA 3.0; Stephen1729 via Wikipedia)