Step 1:
\The three positive integers is
and
.
The sum of three positive integers is
.
The sum of squares is
.
.
Substitute
in
.
.
Apply partial derivative on each side with respect to
.
.


The sum of squares is minimum so, set
.

.
Step 2: \ \
\
Apply partial derivative on each side with respect to
.
.


The sum of squares is minimum so, set
.



.
Substitute
in
.

Substitute
in
.

.
Substitute
and
in
.


.
The three positive integers are
,
and
.
Solution:
\The three positive integers are
,
and
. \ \