If you understand the definition of a mathematical function, a good way to judge it is that any line drawn parallel to the y-axis intersects with the values in the function’s curve only once. The same ...

The ease with which you can create a line graph in Excel on your PC or Mac will do much to dispel the misconception that the program is arcane and unapproachable. With just three clicks of a mouse (or ...

On a non-compact, smooth, connected, boundaryless, complete Riemannian manifold (M,g), some ideal boundary elements could be defined by rays (or equivalently, by Busemann functions). From the ...