Let \(G=\frac{R}{\{0\}} \) and H = {-1, 1} be groups under the multiplication. Then, the map ϕ : G → H defined by \(\phi(x)=\frac{x}{|x|}\) is
1
Not a homomorphism
2
A one-one homomorphism, which is not onto
3
An onto homomorphism, which is not one to one
4
An homomorphism