I agree somewhat with some of the previous answers. You need to understand the problem and come up with your own answers. I came to academia after a lengthy engineering career, and now teach physics. I notice a few things that seem to relate to this question. 1) Students are not taught well enough how to analyze problems. In real life, that is the foundation of /solving/ problems. 2) I find often that texts will present trivial examples to illustrate a point, then jump into more difficult problems as "homework". That leads to 3) I observe that in engineering, when I have a problem to solve, I can find a host of examples. In academia, students who don't dig for those examples find themselves jumping from the text to the problems.
When students are not taught well how to analyze problems, then don't see a host of worked examples, they are left on their own to "discover" what others already know. It's a little like teaching me what numbers are, then asking me to discover algebra, or teaching me the alphabet and a few basic grammar rules, then expecting me to write an advanced paper.
As a hiring engineering supervisor for a large firm, I noted that one of the most critical flaws in the educations of entry level engineers is the inability to tackle problem solving, even at the Master's level.
That all said, there must come a time when the student is challenged to discover new insights. Homework is a good time for that, but only if it is not graded (so that failures don't count against the student, only lack of effort counts against), and only if the student is prepared for the challenges. After all, engineers and scientists don't know the answers to /their/ challenging problems, either, and also make mistakes. I encourage this student to seek out other students to be part of a team, because, just as scientists and engineers have found that solving challenges as part of a team is usually more effective than going it alone, students will find that their progress faster if they participate in team studying (not team cramming, which is quite different, and ineffective in the long run). Recent research indicates that students who take exams on a team basis have better long-term retention than students who take exams as individuals.