Under review — part of this question (a structure or an option) is not clear in the source scan. 4AB is checking it against the original book; the answer shown may change.
$\begin{array}{l}1.1 2.2 3.3 4.4\end{array}$
(a)Greater than – 0.5 au
(b)Equal to – 0.5 au
(c)Less than – 0.5 au
(d)Equal to ζ times – 0.5 au.
Answer
Under review — not yet confirmed.
Answer: A
The source book printed C; on checking, A is correct — see the explanation.
Book printed (c).
Explanation
By the variation theorem any trial function other than the exact one (ζ = 1) gives ⟨E⟩ = ζ²/2 − ζ > −0.5 au — greater than −0.5 au (a).