This book was really helpful. I was trying to tough my way through a book on electrodynamics when I realized I had forgotten everything I knew about vector calculus. Not surprising, it’s been 50 years. The schaum book caught me up enough to understand what I was reading. I probably would just barely pass a test, but at least it helped me remember the days when I was good at math. I miss being young and clever. Being old and grizzled isn’t as much fun.