My freshmen Calculus course used Apostol. I found it a great approach, and it was a lot of fun trying to prove ourselves the theorems in the book. For many stu

My freshmen Calculus course used Apostol. I found it a great approach, and it was a lot of fun trying to prove ourselves the theorems in the book. For many students, intuitively understanding the infinities and infinitesimals in integral calculus come easier than those in differentiation.