# Recent content by John Smith

1. ### Show that PL has matrix

Let PL an QL denote, respectively, projection on and reflection in the line L through the origin with direction vector d = [a b c] =not 0 I got a proplem showing that PL is a matrix. 1/(a^2 +b^2+c^) = Matrix......a^2 ab ac ..........................................ab b^2...
2. ### Linear algebra show eigenvalue

Its okey I did find it out.
3. ### Linear algebra show eigenvalue

I hava a problem finding out how this is showned If A is n x n and r is not 0. Show that CrA(x) = (r^n) * CA(x/r) What rule should I think of in defanition.
4. ### A little proof

Yes thank you I think that I got it now.
5. ### A little proof

I did multiply the equation out and find out that ((v^T)* u)^T = u^T * v But I was wondering if this was enough to show out the proof.
6. ### A little proof

I need help with this proof. We have u and v of size n*1. It is giving that I of size n*n. A = I + u*v^Transpose Proof that if u^T*v is not = -1 then A is reverseble and that A is A^-1 = I - (1 / (1+u^T*V))*uv^T