just a quick question regarding style and convention in mathematics.
My college professor puts the equation of a graph on the y-axis instead of the letter "y"
for instance, putting 2-3cos(x) on y-axis and write x on the x axis.
Is this generally acceptable?
Thanks,
My intuition would be yes, since you are graphing the ordered pairs $(x,f(x))$ anyway. I think I've seen this in books before as well, although usually the function isn't written explicitly.
On the other hand, I've also seen the $y$-axis labelled as $\ln(y)$ before as well; this is referring to the scale with which a function is displayed, rather than the function itself. This style could also become confusing if you were to plot multiple functions on the same graph.
On a third hand, as long as the professor is communicating clearly and consistently with whatever is they are trying to show you, the actual details of "what is generally accepted convention" is usually less important than learning the professor's personal style. This is especially true when moving into more theoretical math, where there might no longer be an accepted convention for how to denote whatever object you are working with.