Ka Wai--Chan>>hi TA Bong_Lee>>hi Shuk Fan--Chau>> good evening!!!!!!! Chun Pong--Derek--Chow>>congrat to ken Shuk Fan--Chau>>i agree Chun Pong--Derek--Chow>>still holapians this night Siu Him--Lau>>holapians are usually quiet Chun Pong--Derek--Chow>>oh where's prof tonight? Siu Him--Lau>>If there is no Q at all, he need not to be here. Chun Pong--Derek--Chow>>i have question tonight Siu Him--Lau>>Lee is here. TA Bong_Lee>>ask please! Chun Pong--Derek--Chow>>i cannot understand the whole chapter of partitioned matrix TA Bong_Lee>>can u raise a more specific question TA Bong_Lee>>it's difficult to talk whole chapter here Chun Pong--Derek--Chow>>why do we have to divide the matrix into several parts? TA Bong_Lee>>sometimes it's convinent for computation Chun Pong--Derek--Chow>>can you be more detail? TA Bong_Lee>>for example TA Bong_Lee>>we have a matrix with property that TA Bong_Lee>>[I A] TA Bong_Lee>>[0I] TA Bong_Lee>>if we want to compute the power three of the matrix TA Bong_Lee>>it's troublesome for us to compute it with original method TA Bong_Lee>>however with the partion matrix property TA Bong_Lee>>we can easily compute it TA Bong_Lee>>where I is n*n and A also Chun Pong--Derek--Chow>>what is n*n? TA Bong_Lee>>n times n Chun Pong--Derek--Chow>>I is identity matrix? TA Bong_Lee>>yes Siu Him--Lau>>I have a Q in last topic. http://algebra.math.ust.hk/matrix_linear_trans/05_composition/exercise5_answer.shtml Siu Him--Lau>>Q.2 in the part "Remark". TA Bong_Lee>>let me c TA Bong_Lee>>what's the prob? Siu Him--Lau>>How to answer it in terms of properties? TA Bong_Lee>>the sys have no unique sol! TA Bong_Lee>>do u know y? Siu Him--Lau>>no TA Bong_Lee>>if we can find non zero sol X for AX=0 TA Bong_Lee>>and if the sys has unique sol say y such that Ay=b TA Bong_Lee>>than X+y also satisfy A(X+y)=AX+Ay=0 TA Bong_Lee>>sorry but A(X+y)=AX+Ay=b TA Bong_Lee>>contradict that y is unique Siu Him--Lau>>thx Siu Him--Lau>>but i need sometime to think about it. TA Bong_Lee>>ok Chun Pong--Derek--Chow>>i am not feeling comfortable, i would like to leave now. bye~ TA Bong_Lee>>take care! TA Bong_Lee>>no one have question? Hiu Nga--Cheung>>see discusion board Shuk Fan--Chau>>good night la!!!!!!!!!!!!! Ka Wai--Chan>>bye TA Bong_Lee>>bye TA Bong_Lee>>u should tell me so late as i have another thing to do TA Bong_Lee>>should not!