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Answer 1 · 2015-07-29T15:06:47

The inverse is {(8,3),(7,12),(9,20),(7,16),(1,23)}. This inverse is not a function.

The inverse of a relation R consists of the reversed ordered pairs from R.

#Inv(R) = {(y,x)| (x,y) in R}#.

Reversing the pairs in the given relation (which is a function), results in:

#{(8,3),(7,12),(9,20),(7,16),(1,23)}#.

This relation is not a function, as it includes two distinct pairs with #7# as the first element..

This is easier to see, if we arrange the pairs by the order of their first element:

#{(8,3),(7,12),(9,20),(7,16),(1,23)} = {(1,23),(7,12),(7,16),(8,3),(9,20)}.#