Subspace projection matrix example | Linear Algebra | Khan Academy

[@UnwrittenLines]

Thanks this helped so much. I can't express my gratitude. Keep up the good work.

[@s.gorelski5277]

The basis set for A is not orthogonal here. The dot product of [1 0 0 1] and [0 1 0 1] is one, not zero. So, all those remaining calculations are faulty.

[@rbmherbert]

this is super helpful- thank you so much!

[@saca8811]

what software are u using to write with?

[@LuisArosIllanes]

thanks, greetings from chile

[@eliordadon2938]

if X has d+1 columns, why the sum of all the elements in P are equal to d+1? why 0

[@ryanjin8343]

What if you try to project R5 onto this subspace? How would you multiply the 1x5 vector by a 4x4 matrix

[@bhaskarrao5254]

In that case the basis will also be 1x5 and the matrix A will also have no. Of rows = 5.....hence altogether u will get a 5x5 matrice at the end

[@randombossgamer1175]

ty!

[@daphnem4882]

where do you get matrix A from?

[@daphnem4882]

like i know he gets it from the span of V but if im working with the subspace x+2y+3z=0, how do i find the columns for A

[@RohanShah-k4j]

How can i do this FASTER?"

[@aamailhot]

this is the foundation of science here...which means boring but useful. deal with it, freshman.

[@ABIYSCGSTEGD]

This video is #112 in this series. Why is time wasted working out every step of the dot product and matrix multiplication? After 111 videos, don't students know this? This makes this video way longer than it needs to be and takes the focus off the main ideas.

[@jeevan288]

You can skip to the part where he finishes doing it.

[@StAchezlesMacs]

just technic.. not science..boring..