Show that the Signum Function f : R R, given by


is neither one-one nor onto.


It is given that f : R R, given by


We can observed that f(1) = f(2) = but 1 ≠ 2.


Thus, f is not one – one.


Now, as f(x) takes only 3 values (1, 0, -1) for the element -2 in co-domain R, there exists any x in domain R such that f(x) = -2


Thus, f is not onto.


Therefore, the signum function is neither one-one nor onto.


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