NIMCET 2018 Question Paper with solutions

Question : 13 of 120

Marks: +1, -0

Which of the following functions is inverse of itself?

Solution:

As we know that any function will be inverse of itself it f (f (x)) = x
By taking option (a) f (x) =

{1-x}/{1+x}

Then f (f (x)) = f

[{1-x}/{1+x}]

{1-({1-x}/{1+x})}/{1+({1-x}/{1+x})}

{{1+x-1+x}/{1+x}}/{{1+x+1-x}/{1+x}}

{2x}/2

⇒ f (f (x)) = x

Go to Question:

Prev Question

Next Question