(iii)

Using product rule, we have

= (x – a)

       = (x – a)

       = (x – a) [1 – 0] + (x – b) [1 – 0]

       = (x – a) + (x – b) = 2x - (a + b)

(ii) Let f(x) = (ax² + b)²

=

Using product rule, we have

      = (ax² + b)

      = (ax² + b)

      = (ax² + b)

      = (ax² +b)[a(2x^{2 – 1})] + (ax² + b) [a(2x^{2 – 1})]

      = (ax² +b)[2ax]+ (ax² + b) [(2ax]

      = 4ax (ax² + b)

(iii) Let f(x) =

Using quotient rule, we have.

                 =

                 =

                 =

                 =

                 =

                 =