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Ha... I've just got the Homework result back... 88 I got -6 for this question.. I know about the two identical lines but it did not used the fact that A is invertible... Actually they just put the invertible fact to confuse because the teacher solution was the same as Dick without using the...

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linear algebra A' is A when two of A lines switched,A Invertible prove (A+A')x=0... Homework Statement A is a n*n matrix A' is the matrix A when two two lines i,j are switched. (switch two random lines is A and you get A') If A Invertible Prove that the system (A+A')x=0 has infinite...

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I've solve it.. Thank you.. AB^2-A = A(B^2-I) Means that A and (B^2-I) are Invertible (B-I)(B+I) are Invertible and so A(B-I) Is Invertible

Homework Statement As in the tile If AB^2-A is a Invertible matrix Prove that BA-A is also a Invertible matrix Homework Equations liner algebra 1 , only the start... The Attempt at a Solution Made many things noting work Thank you

Thank you all , Its a yes no question, But I were interested n how to prove it.. Well I've tried this ... even before I posted the question, But I could not get to any solution. Now I've tried again and made it a(x+z)+b(z+y)+c(y+z)=0 then , x+z = z+y = y+z = 0 Thank you. Thank you...

Homework Statement Well the same as the subject.. (a,b,c) is a Basis of R^{3} does (a+b , b+c , c+a) Basis to R^{3} I have another question .. is (a-b , b-c , c-a) Basis to R^{3} This is know is not true because if I use e1, e2 , e3 I got a error line. Homework Equations start of...

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Thank you I know that I need to prove that g(x) = d(x,E) in any set. This is why I said I tried with Cauchy test for limits, But I did not managed to do it. Any idea of who to prove this? Thank you.

Homework Statement \underline{x} point in R^{n} A \subset R^{n} the distanse between \underline{x} to A is definde as d(\underline{x},A) = \left\{ inf{||\underline{x} = \underline{a}|| | a \in A \right\} A,B are closed Disjoint sets in R^{n} we define f(\underline{x}) =...

I just need a list of integrals.. like that cos^2(x) = 0.5(x+sin(x)cos(x)) and stuff like this for the exam.. Just a list of integrals. Thank you.

MIT opencourseware Single Variable Calculus http://www.youtube.com/user/MIT#g/c/590CCC2BC5AF3BC1 Multivariable Calculus http://www.youtube.com/user/MIT#g/c/4C4C8A7D06566F38

Hello I have a test in calculus.. all of it.. 1 2 and 3 , and I can enter all the stuff I want to the exam.. anyone can suggest me a good integral list book. A book that has allot of integrals, but calculus related.. all the books I've found online are huge and has allot of integrals that I do...

Thank you for your respond. English is not my first language and Sadly I am not sure I understand what you mean in "try taking the dot product of both sides with \textbf{u} \times \textbf{v}" Do you mean that I need to build three equation : First we know that \textbf{u} \times \textbf{v} =...