2. $$f ( x ) = \frac { 1 } { \sqrt { } \left( 9 + 4 x ^ { 2 } \right) } , \quad | x | < \frac { 3 } { 2 }$$ Find the first three non-zero terms of the binomial expansion of \(\mathrm { f } ( x )\) in ascending powers of \(x\). Give each coefficient as a simplified fraction.