Solution
= Solution
The <Taylor series> of the logarithm gives
$$
\log(1+x^2)=x^2-\frac{x^4}{2}+O(x^6).
$$
The first nonzero term is therefore $\boxed{x^2}$. It is positive on either side of the origin, so the <stationary point> is a \b[<strict local minimum>]. In fact $\log(1+x^2)\geq0$, with equality only at zero, making it the <global minimum> as well.