I have gotten from this equation: y=3x into its polar form by substituting x= r cos (theta) and y=r sin (theta) to get me here: r sin (theta) = 3r cos (theta) Substitute and simplify. r sin (theta) - 3r cos (theta) = 0 Subtract 3r cos (theta) from both sides. r [sin (theta) - 3 cos (theta)] = 0 Factor out r from the equation. Now I set both equal to zero like this... r = 0 or sin (theta) - 3 cos (theta) = 0 I am assuming r = 0 is included in the graph of the second equation. So the only solution to the original problem comes from solving the second equation for Theta ---> sin (theta) - 3 cos (theta) = 0 arctan (3) = 1.2490 radians Is 1.2490 radians the correct solution to the original question of convert y=3x into polar form?