Help with function question please? What is f(2) for the given function?

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What is f(2)?

1 Answer
Feb 21, 2018

f(2)=1/3

Explanation:

As f(sqrt(x+1))=1/x

If sqrt(1+x)=2, we have 1+x=4 and x=3

Hence f(2)=1/3

Alternatively let sqrt(x+1)=t, then x=t^2-1

and f(sqrt(x+1))=1/x is equivalent to f(t)=1/(t^2-1)

andf(2)=1/(2^2-1)=1/3