Formula for 2x2 inverse | Matrix transformations | Linear Algebra | Khan Academy

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Figuring out the formula for a 2x2 matrix. Defining the determinant.
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[@khanacademy]

Yes, you could. The Transformation matrix for doing T1 and then T2 (order matters) would be (T2)(T1) -- you could literally take the product of the matrices. This principal is how we got our technique for determining the inverse.

[@yoshimondal9031]

I've been watching your videos, I like how the Linear Algebra videos progress -- all the concepts unfold naturally (like determinants and stuff) instead of being defined and memorizing it.

[@Belgarathe]

correction at 17:06 that negatative 4 in matrix B should be 4

[@CMacDady]

Exactly what I was looking for. Thank you very much for this.

[@fuckooo]

The way you did this is so cool, certainly kicks the ass of my mathematical economics textbook.

[@ricosuave9225]

you explained this in the most difficult way ever, tho you tried so yh

[@Riverdale270]

In T3 you scale both rows at the same time, while in T1 and T2 you do both rows seperately. So I guess it is possible to do T1 and T2 at the same time too?

[@miqqe93]

Very helpful! Thank you.

[@365Pancakes]

Beautiful, thank you.

[@norwayte]

Brilliant. Thank you. Keep on going.

[@Phagocytosis]

Didn't seem that confusing to me, honestly. I have seen some in KA that were somewhat confusing, but not this one. Of course, that might be just me.

[@fozzix3601]

With the 2x2 matrix [Top row: 1, 7] [Bottom row: 3, 20], you can successfully find the inverse by making an augmented matrix with the Identity. However, the determinant of [1,7] [3,20] is Zero, which should mean it has no inverse. What am I doing wrong here?

[@andymoo00]

Ad-bc 1x20-3x7= -1 not zero there's your mistake

[@AcrobaticlCow]

thanks!!

[@MrX-es9su]

thank bro !!!!!!!!!!

[@best-phone]

What the hell youre talking about !!! :D

[@agnestalbot1295]

Electrical Sterling guitar

[@yeahbuddy714]

I fucking love you Khan!

[@ninomatcharashvili9739]

💪✍️👍👍

[@rktiwa]

this is the single confusing video of all those on lin alz...not typical of salman