(a)
\Caluculate the
.
Let
, then
.



.
(b)
\Adjoint the first two columns to right of the
.

Sum of the product along the indicated downward diagonals is
\
.
Sum of the product along the indicated upward diagonals is
\
.
Diffeerence between the sum of downward diagonals and sum of upward diagonals is
\

.
(c)
\Result of
: By using technical method
.
Result of
: By using diagonal method
.
Compare the results
and
.
There is no change in the value of
in both the cases.
(d)
\The general matrix is
.
Sum of the product along the indicated downward diagonals is
\
.
Sum of the product along the indicated upward diagonals is
\
.
Diffeerence between the sum of downward diagonals and sum of upward diagonals is
\


.
(e) No.
\The method of finding the determinant of the
matrix is lengthy process, hence it is not possible to find the determinant of the
matrix using diagonal method.
Consider a
matrix.


.
(a)
.
(b)
.
(c) same answers
and
.
(d)
.
(e) No. Sample example
.