Been given the matrix A=[k,k,0;k^2,2,k;0,k,k] ; indicates an new row
Need to find: a) the determinant of A using cofactor expansion, and
b) the values of k for which A is invertible...
Therefore A is invertable where DetA doesn't = zero, which is for values of k>1, 0<k<1, -2<k<0, and k<-2
It's OK ! (Clapping)
Originally Posted by deragon999
-k4 – k³ + 2k²
= -k²( k² + k – 2)
= -k²(k + 2)(k - 1)
which is easier to solve in (b) than leaving it as -k4 – k³ + 2k².
Good luck with the assignment. due tomorrow is it not?
I think he did it, but didn't show it, right ?
Originally Posted by Dr Zoidburg
most likely. But I figured it looks better assignment-wise to show the factorisation.