Answer:
a = 4.
Step-by-step explanation:
We know that:
[tex]A = \left[\begin{array}{ccc}4&3\\a&3\end{array}\right][/tex]
is a singular matrix, now we want to find the value of a.
We know that a matrix is singular if:
Det [A] = 0
Where remember that the determinant of a 2x2 matrix is given by:
[tex]M = \left[\begin{array}{ccc}k_{11&k_{12\\k_{21}&k_{22}\end{array}\right]\\\\det[M] = k_{11}*k_{22} - k_{12}*k_{21][/tex]
Then the determinant of A is:
Det [A] = 4*3 - a*3
and that must be zero, so:
4*3 - a*3 = 0
Now we just need to find the value of a:
12 - a*3 = 0
12 = a*3
12/3 = a
4 = a
So the value of a is 4.
