I have the following expression
where C is a constant, and y is the variable, which depends on t. What I need to do is to solve this differential equation, but my problem is that this is a math-class (and not a physics-class), so I need to be very rigorous.
Now it is almost mandatory to comment of the argument of a squareroot. What I know is that the solution y is real.
Thus the term C-y(t) cannot be less than zero. But my question is: Does it make sense to talk about the term "C-y(t)" being less than zero, when y(t) is time-dependent?