$\"\"$

\

The function is $\"\"$ .

\

Apply derivative on each side with respect to $\"\"$ .

\

$\"\"$

\

Apply quotient rule of differentiation: $\"\"$ .

\

In this case $\"\"$ and $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

The slope of the tangent is $\"\"$ .

\

$\"\"$

\

To find horizontal tangent by equating slope of the tangent is zero.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

Horizontal tangent at $\"\"$ .

\

$\"\"$

\

Find the points at which the function has a horizontal tangents.

\

Horizontal tangent at $\"\"$ .

\

Substitute $\"\"$ in $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

The point is $\"\"$ .

\

Horizontal tangent at the point $\"\"$ .

\

$\"\"$

\

Horizontal tangent at the point $\"\"$ .