This is one of those hefty references you don’t need to own; you just need to know where to find it. It’s like an oracle; if you want to know what some obscure mathematical concept or theorem is (What’s a Cantor Set?), you go here. The book has wit and humor; you’ll need persistence.
Mathematics: From the Birth of Numbers
1997, 1,093 pages
A cycloid is the curve generated by a point on the circumference of a circle which rolls on a straight line in its plane.
The Conical Helix
The conical helix is a three-dimensional curve formed as if lying on a right circular cone, where it cuts the generators of the surface at a constant angle a.