The function $f: Z→Z$ defined by $f(x)=x^2+x$ is, where Z is set of integer :

one- one many - one on e- one and not onto one - one onto

many - one

The correct answer is Option (2) → many - one $f(x)=x^2+x$ it is not onto as for $f(x)=1$ no x exists for $x=-1,f(x)=0$ $x=0,f(x)=0$ ⇒ it is Many - one