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L e tf: R->R :f(x)=|x|, Prove that fof=f...

`L e tf: R->R :f(x)=|x|`, Prove that `fof=f`

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We know that` (f o f)(x)=f(f(x))`
` f(x)=|x| `
` Rightarrow (f o f)(x)=f(f(n))=|| x||=|x|=f(n) `
` Henceproved.
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