The question is..
lambda = x (i dont know how to type the symbol..)
Let A be n x n square matrix. Suppose that
det(xI-A) = c(x) = x^3- 3x^2 + x + 6..
I know the answer is -6 by substitute lambda@x with 0..
However.. i just want to know.. why should i substitute it with 0..?
Thanks in advance..