Answer:

Step-by-step explanation:
we know that
The angle x belong to the III quadrant -----> given problem
step 1
Find the angle x

Remember that the angle x belong to the III Quadrant
so

step 2
Find angle x/2

step 3
Find tan(x/2)

Whenever you are given a cubic equation, or any equation, you always have to arrange it in a standard form first. For example, if you are given something like this, 3x2 + x – 3 = 2/x, you will re-arrange into the standard form and write it like, 3x3 + x2 – 3x – 2 = 0. Then you can solve this by any suitable method.