The function is
and the point is
.
.
Apply derivative on each side with respect to
.
.
Derivative of the secant function:
.
.
Slope of the tangent is derivative of the function at given point.
\Find the derivative at
.
Slope of the tangent line is
.
Point - slope form of line equation is
.
Substitute the values
and
in above formula.


. \ \
The tangent line equation is
.