Step 1 :
\The function is
.
The tangent line of the function is horizontal, means that, the slope of the tangent line is zero.
\Set slope =
.

Apply formula :
.
Apply power rule of derivatives :
.
Step 2 :
\Solve
.

If
, then the general solution is
, where
is an integer.
.
If
, then
,
If
, then
,
If
, then
, and ..............
At
, 
At
, 
At
,
, and .........
The points on the graph of the function are
.
Step 3 :
\Solve
.

If
, then the general solution is
, where
is an integer.
.
If
, then
,
If
, then
,
If
, then
, and ..............
At
,
.
At
,
.
At
,
, and .........
The points on the graph of the function are
, where
is an integer.
Solution :
\The points on the graph of the function are
and
, where
is an integer.