Ask yourself "is it possible to get a 3 and an odd number at the same time?"
The answer is "yes, because 3 is an odd number"
This is why they are non-mutually exclusive.
Mutually exclusive events cannot happen at the same time. In terms of a venn diagram, mutually exclusive events would be represented by two circles that do not overlap. The overlapping region is where the two events happen at the same time. An example of mutually exclusive events would be flipping a single coin to land on heads and tails at the same time.
The answer for f(x) = sqrt x is the image below. It is neither of these, so check to see if you have more answer choices. (Just make sure to pay attention to the x- and y-values that the graph is plotted on below)