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Question
Let X = {1, 2, 3}and Y = {4, 5}. Find whether the following subset of X ×Y are function from X to Y or not
h = {(1,4), (2, 5), (3, 5)}
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Solution
Given, X = {1, 2, 3} and Y = {4, 5}
So, X × Y = {(1, 4), (1, 5), (2, 4), (2, 5), (3, 4), (3, 5)}
h = {(1,4), (2, 5), (3, 5)}
It’s seen clearly that h is a function as each pre-image with a unique image.
And, function h is many-one as h(2) = h(3) = 5
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