Hi, I'm having trouble figuring this out:
A is an nxn matrix. It's given that A2=A, A=\=0, A=\=I (I is nxn)
prove or disprove: Ax=0 has only the trivial solution
I tried to disprove that with the determinant:
Hence A is singular
BUT im not sure that this det(A2)=2det(A) is right, and I can't fathom why A=\=0, A=\=I (I is nxn) is given, so I suspect I'm mistaken.
help is very welcomed