The functions are ,  and .

(a)

Find the value of .

Consider .

Differentiate with respect to  on each side.

.

Substitute  in the above expression.

Observe the graph of .

From the graph: .

.

Find  and .

 is the slope of the tangent line to the curve  at .

Consider two points on the tangent line to the curve   at .

The two points are  and .

Slope of the tangent line .

.

 is the slope of the tangent line to the curve  at .

Consider two points on the tangent line to the curve   at .

The two points are  and .

Slope of the tangent line .

.

.

Substitute  and  in the above expression.

.

(c)

Find the value of :

Consider .

Differentiate with respect to  on each side.

.

Substitute  in the above expression.

.

Substitute  in the above expression.

.

Find  and .

 is the slope of the tangent line to the curve  at .

Consider two points on the tangent line to the curve   at .

The two points are  and .

Slope of the tangent line .

.

.

Substitute  and  in above expression.

.

(a) .

(c) .