The curve is and
.
Find the points on the curve where the tangent line is horizontal or vertical.
\Slope of the horizontal tangent line is 0.
\Slope of the vertical tangent line is .
Find the slope of the curve.
\Consider .
Differentiate on each side with respect to .
Consider .
Differentiate on each side with respect to .
Slope of the tangent line is first derivative of the curve.
\Slope of the curve is
\Substitute and
in the above equation.
Slope of the tangent line is .
Slope of the horizontal tangent line is 0.
\ or
.
Substitute in
and
.
.
Substitute in
and
.
The points on the curve where the tangent line is horizontal are and
.
Slope of the vertical tangent line is .
or
.
substitute in
and
.
.
Now substitute in
and
.
.
The points on the curve where the tangent line is vertical are and
.
Check :
\The graph of the curve and
.
Observe the graph:
\The curve has horizontal tangent lines at the points and vertical line tangents at
.
The points on the curve where the tangent line is horizontal are .
The points on the curve where the tangent line is vertical are .