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1.Relation and Function
easy
Consider the identity function $I _{ N }: N \rightarrow N$ defined as $I _{ N }$ $(x)=x$ $\forall $ $x \in N$ Show that although $I _{ N }$ is onto but $I _{ N }+ I _{ N }:$ $ N \rightarrow N$ defined as $\left(I_{N}+I_{N}\right)(x)=$ $I_{N}(x)+I_{N}(x)$ $=x+x=2 x$ is not onto.
Option A
Option B
Option C
Option D
Solution
Clearly $I_{N}$ is onto. But $I_{N}+I_{N}$ is not onto, as we can find an element $3$ in the co-domain $N$ such that there does not exist any $x$ in the domain $N$ with $\left( I _{ N }+ I _{ N }\right)(x)=2 x=3$
Standard 12
Mathematics