Let f(x)=x+1x2tanx+sinx.
(i) Differentiate the numerator N(x)=x2tanx+sinx. Simplify your result.
(ii) Differentiate the denominator D(x)=x+1. State the derivative clearly.
(iii) Hence obtain f′(x) using an appropriate rule and simplify the final answer so that no factor remains common in the numerator.