The Determinant of a 4 by 4 Matrix Using Cofactor Expansion (Expansion by Minors)

[@greenxdshadow6635]

I am watching this during online lecture and you taught it 4 times faster than the professor and way better. thank you

[@Mathispower4u]

Glad it was helpful!

[@rikiman7030]

I had trouble with understanding how we eliminate the rows that have the most 0-s, and that costed me some points because I eliminated another number that was not 0, but this helped me realize what we are actually doing, so thank you.

[@emil2405]

Thank you so much! I was struggeling with keeping the correct minus or pluss. Just adding every minor determinant and using (-1)^ rownumber+colomnumber to keep track of sign is much easier. Thanks alot and keep up the good work!

[@Mathispower4u]

Thank you, I appreciate your support. I'm glad I could help.

[@Salamanca-joro]

Thanks 😊 determinants are really fun to solve! I got final exam next Monday 🙌

[@ZainabKashif-d2j]

SO COOL METHOD THIS IS VERY INFORMATIVE.THANK YOU SO MUCH

[@khalidabdirahmanmohamed3340]

Thank you very much for taking your time ,this was very helpful

[@scaanrdirnaa]

Ok one question: We're using the cofactor formula to get the determinant of a matrix, right? But the formula contains other determinants (those of 3x3 matrices).... So how can I find out the determinants of those matrices?

[@scaanrdirnaa]

Ahhh ok, he started explaining it at around 3:20

[@0niichad]

SUPER HELPFUL VIDEO, great teaching!

[@bmariani52]

Can you show a matrix 4x4 without any 0 values in it ? Always using the top row for the cofactors

[@sigma7208]

why so? just do some operations to make zeros

[@alexanderaltali3997]

veyr helpful, thanks for the free service

[@Mathispower4u]

Thank you for your support by leaving a comment. :)

[@schoolboypoodeehoo]

Where do the -1 come from?

[@xander_al4741]

It's used to find the sign of the minor

[@xander_al4741]

You could also just imagine it as
+-+-+
-+-+-
+-+-+

[@anisasea5994]

What happens to the power of i+j why is it ignored?. Example 3+2, in 1(-1)^3+2

[@satviksrinivas8764]

Thank you, this was very helpful.

[@rachelyoo6466]

Is there a faster way to do this😭

[@adenishola144]

Jjk fan be like. Also he showed that if you select rows with zeros most of the work isn’t needed

[@rachelyoo6466]

hey i passed my finals

[@leandroreyes5209]

@@rachelyoo6466HAPPY FOR YOU

[@balloony9497]

They call me "expansion by minors" in my hometown

[@Doofenshmirtz1088]

Can you do it across the first row?

[@Mathispower4u]

Yes, you can use any row.

[@squareroot1697]

What about col 2 had 3 zeros and a 1

[@kevinzebb]

My professor took 2 hours and didn’t make it any more clearer……

[@hellointernet334]

finally understood it, thank you

[@oscarappiahkubi6349]

Where from the (-1)

[@zewdiherring9528]

The formula of a cofactor expansion, which is equivalent to (-1)^I+j minor(A) subscript i,j

[@selenozgultekin3933]

why there is no place for the numbers inside the matrix in the formula, the formula stars with (-1) and does not mention anything else. while wathcing 3x3 videos they also just put (-1) in the beginning

[@mattpine9207]

Can someone explain to me how 5 raised to the 7th is 5. I am not following that explanation.

[@mattpine9207]

Oh wait I think I get it. Im just being silly.

[@niels1318]

thnx bruv very helpfull

[@Mathispower4u]

You are very welcome!

[@gpn962]

Thanks :)

[@ma947]

Thank you very much🤍

[@Mathispower4u]

Welcome!

[@englishlife5838]

YAS. I understand now

[@pranavshaurya6134]

thanks

[@sofiapinnelli2463]

amazing THANK YOU

[@Mathispower4u]

Glad you like it!

[@morinekaranja6871]

Nice

[@Mathispower4u]

Thanks

[@fannypack7705]

Wammi

[@NIWAMANYAJOVITAH]

Thank you very much

[@Mathispower4u]

You are very welcome!