Question

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

What is f(2)?

Answer 1

`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`