Day 33 in Mat225

Today:

• Questions/Comments on old stuff?

• Section 6.1 summary: Inner Product, Length, and Orthogonality

• Section 6.2:
  • The regression problem, in 3-d, with points
    • (-1,-1)
    • (0,0)
    • (1,2)
    (We think of this as a 2-d problem, so how did it end up in 3-d?)

  • The representation problem, in 3-d: writing a vector in terms of an orthogonal basis.

  • section 6.2 summary: Orthogonal and orthonormal sets