The curve is
.
Apply derivative on each side with respect to
.

Product rule in derivatives:
.


Slope of the tangent line is
.
Slope-intercept form of line equation is
, where
is the slope of the line.
The parallel line equation is
.
Write down the equation in slope intercept form.
\
.
Comparing line equation
with 
Slope of the parallel line is
.
Since the slopes of the parallel line are equal, the slope of the tangent line is
.
Equate slope value to
.





Substitute
in the curve.


Point on the curve is
.
Find the tangent line equation.
\Point-slope form of line equation :
.
Substitute
and
in the point - slope form.
\
Equation of the tangent line is
.
\
Tangent line equation is
.