1. The problem statement, all variables and given/known data 2. Relevant equations All included above 3. The attempt at a solution Well, my solution is there in the box at the bottom. I solved for each of the wire sections individually, two half-infinite straight wires and one quarter-wire. My answer at the bottom there is -19μ T (in the k-hat direction). However, the answer in the back of our book is -23.8μ T (same direction of course). I have looked through my equations for 15 minutes and can't see anything wrong with them. Maybe our answer in the book is wrong (it wouldn't be the first time), but I also wouldn't be surprised if I'm making some mistake in my quarter-circle equation. If someone can help me out, I'd appreciate it.