Q6 of 99 Page 42

Let f : R → R : f(x) = |x|, prove that f o f = f.

To prove: f o f = f


Formula used: f o f = f(f(x))


Given: (i) f : R → R : f(x) = |x|


Solution: We have,


f o f = f(f(x)) = f(|x|) = = |x| = f(x)


Clearly f o f = f.


Hence Proved.


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8

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