If f(x)=x2f(x) = x^2f(x)=x2 for x≥0x \geq 0x≥0 and f(x)=xf(x) = xf(x)=x for x<0x < 0x<0, is f(x)f(x)f(x) invertible?
Yes, because it is continuous.
Yes, because it is one-to-one.
No, because it is not one-to-one.
No, because it is not surjective.