#### Answer

$f(-2)=-12$
$f(-1)=-3$
$f(0)=0$
$f( \frac{1}{2})=\frac{9}{8}$

#### Work Step by Step

We are given:
$f(x)=x^{3}+2x$
We evaluate:
$f(-2)=(-2)^{3}+2(-2)=-8+-4=-12$
$f(-1)=(-1)^{3}+2(-1)=-1+-2=-3$
$f(0)=0^{3}+2(0)=0+0=0$
$f( \frac{1}{2})=(\frac{1}{2})^{3}+2(\frac{1}{2})=\frac{1}{8}+1=\frac{9}{8}$