Skip to content
View in the app

A better way to browse. Learn more.

Dragonmount

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

MATH!!!

Featured Replies

  • Replies 66
  • Views 2.6k
  • Created
  • Last Reply

Correct, and you remembered the c!

 

pretty sure you use eulers formula for that one.

 

 

 

 

 

 

 

 

Yep kinda.  Or you could just do what they teach in physics courses and make a good guess.  I don't like guessing much though.

Find the eigenvalues of the matrix:

 

[4 0 1 5 6]

[0 2 1 0 1]

[0 0 0 0 5]

[0 0 0 1 2]

[0 0 0 0 2]

 

There is a really easy way to do this and a harder way to do it.

Find the eigenvalues of the matrix:

 

[4 0 1 5 6]

[0 2 1 0 1]

[0 0 0 0 5]

[0 0 0 1 2]

[0 0 0 0 2]

 

There is a really easy way to do this and a harder way to do it.

 

OK, this ones out of my depth. What on earth is an eigenvalue?

4 2 0 1 2 they are.

 

*loves Matlab*

 

I forgot the easy method to to it. I know the determinant way though.

 

The eigenvalues of an upper triangular matrix are just the diagonal entries xD

Find the eigenvalues of the matrix:

 

[4 0 1 5 6]

[0 2 1 0 1]

[0 0 0 0 5]

[0 0 0 1 2]

[0 0 0 0 2]

 

There is a really easy way to do this and a harder way to do it.

 

OK, this ones out of my depth. What on earth is an eigenvalue?

 

Say you have a linear transformation T.  An eigenvector is a non-zero vector v such that Tv = λv for some scalar λ.  λ is called an eigenvalue.

I've heard good things about Matlab, Maple, and Mathematica, but all I use is my TI-83 plus and Excel.

[-1 0 0 ; 1 2 -1 ; 0 -1 1]

 

That one was long, so I did it with MAtlab again. I know how to do it with determinants, but I can't remember the other way of doing it...

A cool method of inverting a matrix is to augment it with the identity on the right and then row reduce.  If the original matrix is invertible, the left half will now be the identity and the right half will now be the inverse.

A cool method of inverting a matrix is to augment it with the identity on the right and then row reduce.  If the original matrix is invertible, the left half will now be the identity and the right half will now be the inverse.

 

That's the way I used to know, I just forgot if there was a way to do it shorter.

Sweet, that is a neat trick.

 

It beats working out the determinant.

 

For 3x3 and above yeah.  There's also a way to do it with cross products for 3x3 matrices.

  • 2 weeks later...
  • Author

Sometimes I just like to sit down and think about math and patterns and whatnot.  I managed to make up two formulas involving squares and cubes doing that. :D

Well it's been a few years since I've played with linear algebra. I've always liked related rates the most followed by linear algebra. The two are so practical. Differential Equations I didn't like in the least nor did I like non-euclidean geometry. I hate approximations and statistics, but they can be useful especially in modeling molecular constitutes.

 

Well here is one,

 

y"+2y'+2y=0    y(pi/4)=2 y'(pi/4)=-2 

Actually scratch that last one, I have a math question for Seanie:

 

eπi+6.66+(Sin2(x)+cos2(x))/3=?

 

[Edit]

Fixed the 'E', Thank you Crono.

The first one is easy and I know the second one too, but I won't give it away. Shouldn't you use a small 'e' for the second question?  ;)

Well as I'm currently half way through a C4 paper, I'm sick of maths XD

Ill do your questions at some point though ;)

Archived

This topic is now archived and is closed to further replies.

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.