Question

what is adjoint of a matrix . explain and give an example

Answer 1

http://www.youtube.com/watch?v=SaQV4nOqG6M

Answer 2

for a two by two it is easy like taking the inverse but without having to divide by the determinant

Answer 3

i can not understand the cofactors :(

is it also known as inverse of a matrix ?

Answer 4

do you know what an inner product space is?

Answer 5

\[A=\left| \begin{array}{cc} a & b \\ c & d\end{array} \right|\]
\[A_{adj}=\left| \begin{array}{cc} d & -b \\ -c & a\end{array} \right|\]
whereas
\[A^{-1}=\frac{1}{ad-bc}\left| \begin{array}{cc} d & -b \\ -c & a\end{array} \right|\]

Answer 6

so it is almost like the inverse, but you do not have to divide by the determinant