Find a linear approximation of the function $f(x)=\sqrt[3]{1+x}$ at $a=0$, and use it to approximate the numbers $\sqrt[3]{.96}$ and $\sqrt[3]{1.06}$.

$\sqrt[3]{1+x}\thickapprox$
$\sqrt[3]{.96}\thickapprox$
$\sqrt[3]{1.06}\thickapprox$