Let f: R→R be defined by f(x)=x^2, for every x ∈ R. Then f is :

The correct answer is Option (3) → neither one-one nor onto

$f(x)=x^2$

$y=x^2⇒x=\sqrt{y}$

for $x<0$ y don't exist

⇒ Not onto

for $f(1)=1^2=1=(-1)^2=f(-1)$

but $1≠-1$

⇒ Not One one