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)#

and#f(2)=1/(2^2-1)=1/3#