(a)
\The function is
.
Find the secant line passing through the points
and
.
The equation of a secant line passing through two points is 

The equation of secant line is
.
(b)
\Mean value Theorem :
\If
is continuous on
and differentiable on open interval
, then there exists a number
in
such that
.
The function
is continuous on the interval
and differentiable on the interval
.
So there exists a number
in
such that
.

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


The value of
in the interval
is
.

(c)
\Find the equation of tangent line passing through
and is parallel to the secant line.
The secant line equation is
.

Compare the above equation with the slope intercept form
.
The slope of the secant line is
.
Point slope form of the equation is
.

Therefore, the equation of tangent line is
.
(d)
\Graph the function and tangent line
.
.gif\")
(a) The equation of secant line is
.
(b) The value of
in the interval
is
.
(c) The equation of tangent line is
.
(d)
\
.