Which of the following functions from `A` to `B` are one-one and onto? `f_1={(1,\ 3),\ (2,\ 5),\ (3,\ 7)};\ \ A={1,\ 2,\ 3},\ \ B={3,\ 5,\ 7}` (ii) `f_2={(2,\ a),\ (3,\ b),\ (4,\ c)};\ \ A={2,\ 3,\ 4},\ \ B={a ,\ b ,\ c}` (iii) `f_3={(a ,\ x),\ (b ,\ x),\ (c ,\ z),\ (d ,\ z)};\ \ A={a ,\ b ,\ c ,\ d},\ \ B={x , y ,` `z}`

Explanation

(i) one-one:-


`f_{1}(1)=3 \quad f_{1}(2)=5 \quad f_{1}(3)=7`.


Every element of `A` has different images


Since, codomain `=` range.

`\Rightarrow f`, is onto.

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