coversnptoandindndinglectwett-29ffo.am?g?mdt • Review t office
hours : complements
later next week ( s-me on weekend) • Practice problems :
soon , likely this weekend
#
Question suppose A is nxr A - Ta , AJ . .
.
what is ATB ? Ti ER "
so@
÷
Questions If ( T . . . - r
Deff If ATA - - Ir ,
we say A has
A is called an
[email protected] are rank A
.
how are these related ? 7eI¥ P rank A = rank ( ATA) A mxn
in particular , if thecolumnsofttarelithenATA is inv! ? I ,
rank Ash
'
. : Ai = o ! ! y-
13 NOV 2020
car crashes Xi Yi
y = at bx
>
- =
W = im A dim n
V is 1124 ) .
subspace of RM .
god . solve : find closest pt on W to J EV
• prwiy ) = ?? = AI - find I
⇐ 5 - AI c- ( im AT HW !
⇒ J - AI E Ker CAT) ⇐
⇒ Atty- AI ) = 8
⇐ AtAx=A .
"normal equation -
'
AT J
prwr-AIAT.AT#T !
-
e.⇒ ay: "
"
