The trigonometric equation is
.

Apply zero product property.
\
or 
or
.
Solve
.

The general solution of
is
, where
is an integer.
The solution is
, where
is an integer.
Find the solutions on the interval
.
If
,
.
If
,
.
Thus, the solutions of
are
and
on the interval
.
Solve
.

The general solution of
is
, where
is an integer.
The solution is
, where
is an integer.
Find the solutions on the interval
.
If
,
.
If
,
.
Thus, the solutions of
are
and
on the interval
.
\
Therefore, the solutions of
are
,
,
and
on the interval
.
\
Therefore, Vijay
s solutions are correct.
Vijay
s solutions are correct.