(a) Show that a symmetric matrix N is negative definite if and only if K = - N is positive definite.
(b) Write down two explicit criteria that tell whether or not a 2 x 2 matrix

is negative definite.
(c) Use your criteria to check whether
(i)

(ii)

(iii)

are negative definite.

Transcribed Image Text:

N= 5 5 2 1