This is a matrix question.

Question

R is the matrix (3r 1)
(s 2s)

1. State, in terms of s and r the determinant of R
2. If r=1/3 and s=4 determine the inverse of R
3.State the pair of r and s not including 0, which would make the matrix R a singular matrix

Answer 1

det = 6rs-s
R is singular if s(6r-1) = 0, so r=1/6 and s is anything

R^-1 =
1/4 *
(8,-1)
(-4,1)