
#1
Feb508, 07:07 PM

P: 62

can u gave me some examples of injective function that is not surjective.
Is f(x)=y a injective function that is not surjective? 



#2
Feb508, 09:43 PM

P: 1,635

what about f:N>N defined by f(n)=3n where n is from naturals, and N is the set of naturals.
1>3 2>6, so this function is injective since when f(n_1)=f(n_2)=>3n_1=3n_2=>n_1=n_2, but it is not surjective since there exists at least a numberf in the second N, in our case for example 1 that there are no numbers in N(the domain) such that when f(n)=1. 



#3
Feb508, 09:45 PM

P: 1,635

You can go and define such functions as much as you wish, for i just made that example up. OR are you looking for any other example in particular?




#4
Feb508, 10:37 PM

P: 363

can u gave me some examples of injective function.
f:[0,1] > R given by the identity function.
f:R > C given by identity function. 


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