Problem

Part II Fill in the blanks

10. The third term of the Maclaurin series (i.e. the Taylor series centred at $x=0$) of $\arcsin(3x)$ is $\underline{\quad(11)\quad}$ (note that the answer should be a monomial in $x$; the term of $x^0$ is counted as the 0-th term). The radius of convergence of the series is $\underline{\quad(12)\quad}$.