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#1 Help Me ! » Matrix algebra determinant proof help » 2011-04-05 13:53:10

Fifa
Replies: 2

The problem is... "If the entries in each row of an nxn matrix, A, add up to zero prove that the determinant of A is zero. (Hint: Consider the product AX where X is the nx1 matrix, each of whose entries is one.)"

Any help would be appreciated.

#2 Re: Help Me ! » Matrix algebra: Prove AB-BA cannot equal I2? » 2011-02-22 14:25:04

Oh haha the rest of it wasn't up yet, now it makes sense, thanks so much!

#3 Re: Help Me ! » Matrix algebra: Prove AB-BA cannot equal I2? » 2011-02-22 14:15:12

I understand everything you did, but I am still confused on how bg-cf=1 can disprove this.

#4 Help Me ! » Matrix algebra: Prove AB-BA cannot equal I2? » 2011-02-22 13:44:45

Fifa
Replies: 5

The question for my matrix algebra class is: show that there is no 2x2 matrix A and B such that AB-BA= I2 (I sub 2, identity matrix, sorry can't write I sub2)

I2: |1 0|
     |0 1|

We obviously can't prove it with a specific example, it has to work for all 2x2 matrices. anyone know how to prove this? Thanks for the help!

#5 Re: Help Me ! » Chances of getting tail on a coin before 1 on a die? » 2010-01-16 15:05:26

Sorry, to clerify the coin is flipped first, then the die rolled

#6 Help Me ! » Chances of getting tail on a coin before 1 on a die? » 2010-01-15 13:47:10

Fifa
Replies: 4

What is the chance of getting a tail on a coin before getting a 1 on a die? I was trying it and I think it involves a limit, I am just not sure how to set it up. Thanks in advance!

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