Let f: X Y be a function.True or False?A sufficient condition for f to be one-to-one is that for all elements y in Ym there is at most one x in X with f(x)= y. Solution true. A function f from X to Y is called one-to-one (or 1-1) if whenever f (x) = f (y) then x = y. No element of Y is the image of more than one element in X. that is one-one function has an inverse that is also a function..