Let, that O is the origin. and I think the question should
read as what is the equation of line AB so (or such) that the triangle ΔAOB is
equilateral.
Given y=√3x,slope=√3,⇒α=tan−1√3=60∘
similarly, as y=−√3x,⇒β=60∘, as shown in the figure.
⇒∠BOA=180−60−60=60^o
For ΔOAB to be equilateral, line AB has to be parallel to the x-axis.
Hence, equation of line AB that passes through P(2,2)and is parallel to
the x-axis is :y=2