Thread: Matrices question?

(a) Calculate the inverse of A, where

|1 −2| = A
|4 −2|

(b) Find the value of k for which the matrix B is singular, where

|1 5 −3| = B
|3 −3 3|
|2 13 k|

*give ur workings and clear answer.

Okay, you just need some facts to get yourself going on this one.

If you have a matrix that we'll call A:

a b
c d

then the INVERSE of it will be

[ 1/ (determinant of A) ] * d -b
-c a

The inverse of a 2x2 matrix - mathcentre

That link above has it all summarised quite nicely.

A matrix is SINGULAR if its determinant is zero.

*give ur workings and clear answer.

Once again, I will leave that to you.