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Question
Give an example of a map which is one-one but not onto
Solution
Let f: N → N, be a mapping defined by f(x) = x2
For f(x1) = f (x2)
Then, `x_1^2 = x_2^2`
x1 = x2 ......(Since x1 + x2 = 0 is not possible)
Further ‘f’ is not onto, as for 1 ∈ N, there does not exist any x in N such that f(x) = 2x + 1.
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