Suppose $y$ is a function of $x$, i.e. $y=f(x)$. (just univariate) Would both of the following notations for the first derivative of $y$ (with respect to $x$) be correct and usable?
- $\dfrac{dy}{dx}$
- $\dfrac{dy(x)}{dx}$
The second one is just to emphasize that $y$ is a function of $x$, even without which it seems obvious. But this notation is still okay to use, correct?
The simple answer is yes, it's quite common to omit the dependent variable but including is just as correct.