openwebwork/webwork-open-problem-library — pull request #56 by Dick-Lane (2013-11-12 23:27:39+00:00)
Title: Minimal change so the "answer" does not contradict the constraint.

On p540 of SRW-5, the corresponding problem is 23 [without constraint].

An alternative revision would just remove the first clause, leaving
If \sin(x - pi/2) = A \, cos(x), then A = [box].