is
Replacing
expanding with respect to R1
= 2(-14) - (4)(-2)
= -28 + 8 ≠ 0
.............................................(i)
Also A does not possess any minor of order 4, i.e. 3 + 1
..................................................(ii)
From Equations (i) and (ii), we get
p(A) = 3 i.e. rank of A is 3.
then
45. The eigen vectors of a real symmetric matrix corresponding to different eigen values are
AT=A
Let α1 and α2 be different eigen values of matrix A, and X1 and X2 be the corresponding vectors, then
AX1= α1X1 and AX2 = α2X2
Taking transpose of the second equation
(AX2)T= (α2X2)
X2TAT= α2.X2T 2X2T
But AT-A
Post multiply by X1, we get
XT2AX1 = a2 X2T X1
But AX1 = a1X1
XT2 a1X1 = a2 X2T X1
(a1 - a2) X2TX1 = 0
Since a1 a2, a1 - a2 0
X2TX1 = 0 i.e. X2 and X1 are orthogonal.