/sci/ - Science & Math

>>11686599
The slope is defined as the change of y over the change of x. Because of this, a horizontal line has the slope 0, as its y-coordinate stays constant, but a vertical line has a constant x-coordinate giving you whatever/0. We could have the roles of x and y reversed, however, and then it would follow that vertical lines have the slope 0 and horizontal ones don't have it defined. I don't know if it was Descartes himself who decided to divide by the change of x instead of y, but it is more intuitive that way. I mean, think about how you would think about the slope of a mountain.