9758/2022/P1/Q02

It is given that $\mathrm{f}(x)=\tan ^{-1}(\sqrt{2}+x)$.
(a) Find $\mathrm{f}^{\prime}(x)$ and $\mathrm{f}^{\prime \prime}(x)$.

[3]

(b) Hence find the first three terms of the Maclaurin series for $\mathrm{f}(x)$. Give the coefficients correct to 3 significant figures.

[3]