Is image used to mean the same thing in the next two sentences (see options)?

The number 6 is the image of 3 under f that is defined as f(x) = 2*x.

The image of f(x) = x^2 is the set of all non-negative real numbers if the domain of the function is the set of all real numbers.

Pick from:
a). different meanings.
b). the same meaning.
b).