The functions are
,
and
.
Consider
.
Apply derivative on each side with respect to
.

Consider
.
Apply derivative on each side with respect to
.

Find
.

Substitute
.

Slope of the tangent is the derivative of the function at the point.
\Find slope of the tangent at
.
Substitute
in
.

.
Slope of a tangent line is
.
Find the point corresponding to the value
.
Substitute
in
.

Substitute
in
.
Now obtained point is 
Point-slope form of a line equation is
.
Substitute
and
in point-slope form.


The tangent line equation is
.
The tangent line equation is
.