Solution
= Solution
For $f(x)=\sqrt x$, the first two <derivatives> at one are $f'(1)=1/2$ and $f''(1)=-1/4$. The <Taylor expansion> begins
$$
\boxed{\sqrt x=1+\frac12(x-1)-\frac18(x-1)^2+O((x-1)^3)}.
$$
All three displayed terms are nonzero terms of the expansion about one.