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13. QR Decomposition (Gram Schmidt Method) example ( Enter your problem )
  1. Example `[[1,-1,4],[1,4,-2],[1,4,2],[1,-1,0]]`
  2. Example `[[3,2,4],[2,0,2],[4,2,3]]`
  3. Example `[[1,-4],[2,3],[2,2]]`
  4. Example `[[1,2,4],[0,0,5],[0,3,6]]`

4. Example `[[1,2,4],[0,0,5],[0,3,6]]`





Find QR Decomposition (Gram Schmidt Method) ...
`[[1,2,4],[0,0,5],[0,3,6]]`


Solution:
Here `A` = 
`1``2``4`
`0``0``5`
`0``3``6`


`q_1'``=a_1` = 
`1`
`0`
`0`
 = 
`1`
`0`
`0`


`r_(11)=||q_1'||=sqrt((1)^2+(0)^2+(0)^2)=sqrt(1)=1`

`q_1 = 1/(||q_1'||) * q_1'` = `1/1 * `
`1`
`0`
`0`
 = 
`1`
`0`
`0`


`r_(12)=q_1^T * a_2` = 
[`1``0``0`]
 `xx` 
`2`
`0`
`3`
`=2`


`q_2'``=a_2-r_(12) * q_1` = 
`2`
`0`
`3`
 `-2` 
`1`
`0`
`0`
 = 
`0`
`0`
`3`


`r_(22)=||q_2'||=sqrt((0)^2+(0)^2+(3)^2)=sqrt(9)=3`

`q_2 = 1/(||q_2'||) * q_2'` = `1/3 * `
`0`
`0`
`3`
 = 
`0`
`0`
`1`


`r_(13)=q_1^T * a_3` = 
[`1``0``0`]
 `xx` 
`4`
`5`
`6`
`=4`


`r_(23)=q_2^T * a_3` = 
[`0``0``1`]
 `xx` 
`4`
`5`
`6`
`=6`


`q_3'``=a_3-r_(13) * q_1-r_(23) * q_2` = 
`4`
`5`
`6`
 `-4` 
`1`
`0`
`0`
 `-6` 
`0`
`0`
`1`
 = 
`0`
`5`
`0`


`r_(33)=||q_3'||=sqrt((0)^2+(5)^2+(0)^2)=sqrt(25)=5`

`q_3 = 1/(||q_3'||) * q_3'` = `1/5 * `
`0`
`5`
`0`
 = 
`0`
`1`
`0`


`Q``=[q_1,q_2,q_3]` = 
`1``0``0`
`0``0``1`
`0``1``0`


`R` = 
`r_(11)``r_(12)``r_(13)`
`0``r_(22)``r_(23)`
`0``0``r_(33)`
 = 
`1``2``4`
`0``3``6`
`0``0``5`




checking `Q xx R = A?`

`Q xx R` = 
`1``0``0`
`0``0``1`
`0``1``0`
 `xx` 
`1``2``4`
`0``3``6`
`0``0``5`
 = 
`1``2``4`
`0``0``5`
`0``3``6`


and `A` = 
`1``2``4`
`0``0``5`
`0``3``6`


Solution is possible.




This material is intended as a summary. Use your textbook for detail explanation.
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