For the benefit of Calc'2 users that want to avoid complex numbers, passages using them are marked specially. Even for interested calculus audience however, I do not recommmend to screen out complex numbers.
Color version with complex number references in red: ps format --- pdf format --- dvi format (your dvi driver may ignore the color and render it black, \special's are for dvips)
Black and white version with complex number references in gray: ps format --- pdf format --- dvi format (your dvi driver may ignore the gray and render it black, \special's are for dvips)
Version in which complex number references are not color-coded: ps format --- pdf format --- dvi format