I have here a little problem, where I am just not really sure how to tackle this:
Let R be a relation on the real numbers, with R = {(log2(x), x)| x e R+}. Determine whether this is a function and if so, determine whether it is injective and/or surjective.
My problem here is that I am not quite sure how to look at this. The logarithm is clearly a function over the domain R+, but in the relation log2(x) would be the the argument for the function and x is the value of the function. Would it be correct to assume that this is actually defining the function f(x) = 2^(log2(x)) = x with R+ as the domain?