Through years of tutoring, I’ve observed three distinct user archetypes:
Before discussing the manual, we must appreciate the textbook itself. Mary L. Boas wrote her text to bridge the gap between "calculus for engineers" and the brutal mathematical demands of quantum mechanics, electrodynamics, and thermodynamics.
This pedagogy is intentional. Boas wants you to struggle. But uncontrolled struggle leads to frustration and, worse, incorrect internalized methods. The solutions manual acts as a safety net and a tutor.
However, students often refer to a broader ecosystem of solution resources, including:
Students consistently report five chapters where the solutions manual is nothing short of a lifeline.
You tell yourself, "I'll just glance at the solution to get started." Then you copy it. Then you do it again for ten problems. Then you cannot solve a single problem on the test.