(a) The equation is .

Find .

Apply on each side.

Differentiate with respect to .

.

(b)

Find the slope of the tangent line.

Derivative of the function is slope of the tangent line.

(i) At the point :

Substitute in .

when .

(ii) At the point :

Substitute in .

.

(iii) At the point :

Substitute in .

.

(c)

Tangent line will not exist at a point if the derivative at that point does not exist.

Derivative will not exist if denominator is zero.

At , is undefined.

(a) .

(b) when ; ; .

(c) .