If you cannot obtain an official solution manual, consider these high-quality substitutes:
Close the solution manual and re-derive the answer entirely from memory. This cements the method in your long-term memory. Solution Manual Basic Complex Analysis Marsden
Search for the specific Marsden problem (e.g., “Marsden Hoffman exercise 4.2.7”). Many have been answered by the community. You can even post your attempt for feedback. If you cannot obtain an official solution manual,
Beyond the answer, a good solution manual would explain why the integral over the semicircle vanishes (Jordan’s lemma) and why a > 0 is necessary. This transforms a rote answer into a learning tool. Solution Manual Basic Complex Analysis Marsden
To illustrate the value of a solution manual, consider a classic Marsden problem (Chapter 5, Residue Theorem):