The points on the curve $y=x^3$, the tangents at which are inclined at an angle of 60° to x-axis are:

$(3^{-1/4},3^{-3/4}),(-3^{-1/4},-3^{-3/4})$ $(3^{-1/2},3^{-2/5}),(-3^{-1/3},-3^{-2/3})$ $(3^{1/4},3^{-2/5}),(-3^{1/2},-3^{-1/2})$ None of these

$(3^{-1/4},3^{-3/4}),(-3^{-1/4},-3^{-3/4})$

$\frac{dy}{dx}=3x^2⇒60°=3x^2⇒\sqrt{3}=3x^2⇒x^2=\frac{1}{\sqrt{3}}$ $⇒x=±3^{-1/4},y=±3^{-3/4}$ ⇒ Point = $(3^{-1/4},3^{-3/4}),(-3^{-1/4},-3^{-3/4})$