Define the projective line CP¹as follows:

CP¹= {(z, w) C²|(z, w) =/= (0, 0)}/ ,

where (z₁, w₁) (z₂, w₂) if and only if z₂= z₁, w₂= w₁for some C^*.

Prove that CP¹equipped with the quotient topology is homeomorphic to S².