In my program, there are many functions relying on spatial coordinates: x, y, and z, which are also functions of time t, i.e., composite function. I need to differentiate some functions for example f:
D[f[x[t], y[t], z[t]], t]
But because those coordinates appear so frequently, when I write x[t] instead of x my program becomes lengthy and lacks readability. So, how can I declare those coordinates as functions of time t at the start to tell Mathematica that the differentiation is relative to t, so I can use x, y , and z, afterwards as an abbreviation.