Answer
polynomial, $n=2$,
$f(x)=-\frac{1}{2}x^2+\frac{1}{2}$, $-\frac{1}{2}x^2$, $\frac{1}{2}$.
Work Step by Step
Step 1. Given $f(x)=\frac{1-x^2}{2}$, we can determine it is a polynomial function.
Step 2. We can identify the degree as $n=2$.
Step 3. In standard form $f(x)=-\frac{1}{2}x^2+\frac{1}{2}$. We can identify the leading term as $-\frac{1}{2}x^2$ and the constant term as $\frac{1}{2}$.