The equation of the curve is  and point .

Definition:

Slope of the tangent to the curve  at point : .

(a)

The curve equation is  and point is .

Substitute  in the above expression.

Slope of the tangent line is .

(b)

The tangent line at point  :

Substitute  in slope of the line .

Point-slope form of line equation: .

Substitute  , and   in the slope-intercept form.

Tangent line equation at  is .

The tangent line at point :

Substitute  in slope of the line :

Point-slope form of line equation: . 

Substitute  , and  in the slope-intercept form.

Tangent line equation at  is .

c)

The graph of the function and the tangent lines:

(a) Tangent line equation at  is .

(b) Tangent line equation at  is .

(c) The graph of the function and the tangent lines:

.