Polar coordinates

/sci/, what would be the best method for solving the following type of problem, "Determine whether the point lies on the curve r^2 = sin(3x) [1,-5pi/6]"

Rewrite the equation in polar form, remembering that x = r*cos(theta):
r^2 = sin(3r*cos(theta))
Fill in the given coordinates:
r^2 = 1
sin(3*cos(-5pi/6)) = sin(3sqrt(3)/2) != 0

Conclusion, the point is not on the curve.