It may seem like an odd question to ask and until now the answer is not all the time yes. Just as we identify that a solution to a differential equations exists does not implies that we will be capable to determine it.

In differential equations in a first course (as this one) the third question is the question about on what we will concentrate on. Here we will answer the first two questions for particular and fairly simple cases, but mainly of our efforts will be concentrated upon answering the third question for as broad a variety of differential equations as possible.