Question

The function $f:R\to R$ defined by $f\left(x\right)=\frac{x^2}{1+x^2}\forall x\in R$ is

• A. one one but not onto
• B. onto but not one one
• C. a bijection
• D. neither one one nor onto

Answer 1

Answer: (D)

neither one one nor onto

Since, $f(-1)=f\left(1\right)$
Therefore, it is not one-one
and $f\left(x\right)>0$ always
It is neither onto
Ans: D