The book I used in college was "Mathematics for Finance: An Introduction to Financial Engineering" by Marek Capinski and Tomasz Zastawniak. You can easily find

The book I used in college was "Mathematics for Finance: An Introduction to Financial Engineering" by Marek Capinski and Tomasz Zastawniak. You can easily find (legal) PDFs of it online. I should say that a lot of people in my class really didn't like the book. Personally I thought it was fine.