Using Eq. (4), apply the singularity test to the matrices in Exercises 13–16. Show that there is no real scalar , such that A-11 is singular. [Note: Complex eigenvalues are discussed in Section 4.6.] -2 -1 3 -2 13. A = 14. A= 5 2 5 -3 2 1 15. A= 16. A = [ =[ [:-] [:] 1=[:] 1 2 1 1 17. Consider the (2 x 2) symmetric matrix a b AE