Question:
Mark $(\sqrt{)}$ against the correct answer in each of the following:
$\int \frac{d x}{\left(9+4 x^{2}\right)} d x=?$
A. $\frac{1}{2} \tan ^{-1} \frac{2 \mathrm{x}}{3}+\mathrm{C}$
B. $\frac{1}{6} \tan ^{-1} \frac{2 \mathrm{x}}{3}+\mathrm{C}$
C. $\frac{1}{6} \tan ^{-1} \frac{3 x}{2}+C$
D. none of these
Solution:
