Ahh that's a typo. Good eye. Thanks for pointing it out, and fortunately that term immediately gets cancelled out and the typo doesn't get carried through the problem. Cheers and thanks for contributing!
@NM can you please elobrate the "sum of minors along principal diagonal" like there is no "60" and "8" element in the matrix, I came here for learning what you wrote, I know for 2*2 matrix but I wanted to learn about 3*3 or n*n matrix.
Thank you so much for the awesome video. Very easy to understand and you went above and beyond and explained so much more which really helped :) subscribed!
These things are a massive pain. The problems I have encountered so far don't really have any zeroes so I have to row reduce which causes a lot more lamda's to be distributed in the matrix ._.
Don't row reduce a matrix and then find characteristic polynomial. It will most likely not be the characteristic polynomial if the original matrix. If your prof is mean and doesn't put a through zeros throughout, you just have to crunch all the numbers in the whole thing.
@@Engineer4Free oh yeah I know! 😅 I cant row reduce a matrix without applying the "lambda form" in the diagonal. I meant I have to row reduce the lambda form matrix and those things get so baddd. I have to find a common denominator to pull out to make finding the determinant easier.
Will the characteristic polynomial ever have a constant in it? Im running into the issue of finding the eigenvalues through factoring with a constant hanging out at the end :')
The method of finding the determinant that I use in this video only works for 3x3 matrices. I like to use this method for 3x3 because I find it quicker than cofactor expansion. For 5x5 or any other size, you should just do cofactor expansion. Here's an example of how to do it: www.engineer4free.com/4/find-the-determinant-of-a-3x3-matrix-using-cofactor-expansion
when you were taking the 2 columns to the side, why did you use 30 instead of 3?
Ahh that's a typo. Good eye. Thanks for pointing it out, and fortunately that term immediately gets cancelled out and the typo doesn't get carried through the problem. Cheers and thanks for contributing!
was about to say the same thing lol@@Engineer4Free
Yeah lucky for the zero!
it's amazing how you can explain this so well under 4 min while i don't get nothing out of 1 hour of my professor's online class
Glad I can help! More at engineer4free.com/linear-algebra =)
R
=
6678
P 3:53
Thank you, you just saved my life and my exam that will start in 3 hours!
You're welcome! How did it go?
Damn, what a coincidence. My exam starts in 3 hours too!
@@webstime1 my exam starts in 2 hours too! 😁
2 hours of mine
so useful and brief. Amazing video! A handy shortcut to understand what is written in those frustrating linear algebra books. Thank You So much!
Glad you enjoyed it!! =)
Shortcut: char eqn of 3*3 matrix:
£^3 - tr (A) £^2 + (sum of minors along principal diagonal)£ - det(A) = 0
Tr(A) = 2+4+30=36
Minor sum = 0+60+8= 68
Det(A)= 0
£^3 - 36 £^2 + 68 £ = 0
@NM can you please elobrate the "sum of minors along principal diagonal" like there is no "60" and "8" element in the matrix, I came here for learning what you wrote, I know for 2*2 matrix but I wanted to learn about 3*3 or n*n matrix.
Minor of 2 is 120-120 =0
Minor of 4 is 60-0=60
minor of 30 is 8-0 is 8
@@nm3940 THANKS A LOT! REALLY!!! IT'S A GREAT HELP 😌
Thank you so much for the awesome video. Very easy to understand and you went above and beyond and explained so much more which really helped :) subscribed!
Awesome, thanks for leaving the comment Sami, happy to have you around =)
Very informative simplified video. Thank you ❤️
Thank you sir... Iam shocked about the calculations of determinant... Simple trick ... Solved in few seconds...
Woh Sir... 🔥🔥👌👌😍
can we use it for 4x4 matrix?
Please explain
This is an awesome explanation thank you.
fr this is good work. Keep it up
Thank you for sharing this _great_ mathematical *LIFE HACK* !!
It's really helpful thank you👍
Glad to hear it!! The full playlist is here: engineer4free.com/linear-algebra 🙂
This is amazing, thanks,
Thanks for leaving the comment!! There are more examples @ engineer4free.com/linear-algebra =)
@@Engineer4Free thank you, I just checked. You might be saving my session by these videos
thank you you better than my professor
=) thanks Gyumin
Merci pour la vidéo 😇
=)
will the answe be the same if we did determinant of (Labda I - A) instead of (A- Lambda I)?
i am curious about this as well
killed it, ty
thanks a lot!! this really helped me!
how did you find the roots?
thanks a lot! straight to the point.
what's the approach for simplifying a polynomial when we have a constant in the equation?
Thank You
You could've easily expanded the deteminant from first column. There are 2 zeroes in it. That'd me quicker n simpler.
Good eye!!! I am just very used to defaulting to the method used in this video I didn't even notice that that would have been quicker =)
Thanks
These things are a massive pain. The problems I have encountered so far don't really have any zeroes so I have to row reduce which causes a lot more lamda's to be distributed in the matrix ._.
Don't row reduce a matrix and then find characteristic polynomial. It will most likely not be the characteristic polynomial if the original matrix. If your prof is mean and doesn't put a through zeros throughout, you just have to crunch all the numbers in the whole thing.
@@Engineer4Free oh yeah I know! 😅 I cant row reduce a matrix without applying the "lambda form" in the diagonal.
I meant I have to row reduce the lambda form matrix and those things get so baddd. I have to find a common denominator to pull out to make finding the determinant easier.
It's great 😍😍
Will the characteristic polynomial ever have a constant in it? Im running into the issue of finding the eigenvalues through factoring with a constant hanging out at the end :')
ooofff nice thanks
for a 5*5 do we also get 2 colums, is it the same? cos It won't work with one I am trying
The method of finding the determinant that I use in this video only works for 3x3 matrices. I like to use this method for 3x3 because I find it quicker than cofactor expansion. For 5x5 or any other size, you should just do cofactor expansion. Here's an example of how to do it: www.engineer4free.com/4/find-the-determinant-of-a-3x3-matrix-using-cofactor-expansion
You're awesome
Thanks dawg 🙌
Sir Kindly continue the Dynamics course again?
Hey Irfan, I've got about 15 more linear algebra videos planned before I start working on Dynamics again. Should be getting back into it next month.
Engineer4Free Thanks Sir. Kindly do it as I am failing this course and earlier I got a B+ in Statics because of your videos.
what happen if our matrix 5*5 ?
No problem, follow the exact same process. It will just take longer to solve.
@@Engineer4Free But in case of 5x5, we will join the first 4 columns instead of the first 2 columns in case of 3x3 right?
Tnx
I'm sitting here like how did that guy write so fast?
😏
When You got to the final step and meant to simplify to get the answer I got confused fr
3 Not 30
i was wandering too
Love how you speed up the nonsense computations
2 for 1🎉
🙂
@@Engineer4Free thanks for this, by the way. Much appreciated.
Basic level for Indian 12 th grade
first comment
this is not help
You're so sweet bro #i just fancy how amazing you are @HillaryNdiro ..