Solve the equation 6x^3 + 11x^2 - 3x - 2 = 0

Hence, find the values of angle [D] between 0 and 180 degrees, which satisfy the equation 6 tan[D]^2 + 11 tan [D] - 3 = 2 cot [D]

I have solved the cubic equation by factor theorem - its answers are

-2, -1/3, 1/2

I can't seem to find the values of angle [D], since the new equation doesn't exactly tally with the cubic one.

Please assist.

Thank you.