Use synthetic division to find the function values.
$f(x)=x^{4}-16 ;$ find $f(1), f(-1)$
$f(1)=\square$ (Type an exact answer, using radicals as needed)
$f(-1)=\square$ (Type an exact answer, using radicals as needed.)
So, $f(1)=\boxed{-15}$ and $f(-1)=\boxed{-15}$
Step 1 :Substitute $x=1$ into the function $f(x)=x^{4}-16$ to find $f(1)$
Step 2 :Calculate $f(1)=1^{4}-16=-15$
Step 3 :Substitute $x=-1$ into the function $f(x)=x^{4}-16$ to find $f(-1)$
Step 4 :Calculate $f(-1)=(-1)^{4}-16=-15$
Step 5 :So, $f(1)=\boxed{-15}$ and $f(-1)=\boxed{-15}$