Thread can be closed, I have got the answer.
You only need to solve $\displaystyle \cos x = \frac{\sqrt{3} - 1}{2}$ (why?).
Note that you only need them in the form k pi, with k correct to one decimal place. So use technology to get decimal approximations of all solutions and then solve for k, correct to one decimal place.
Eg. One solution is x = 1.19606. So $\displaystyle 1.19606 = k \pi => k = \, .....$, correct to one decimal place.
Deleting your question and proclaiming that you have the answer is NOT good form.
1. Other members might be interested in the question and its solution. MHF would be a pretty crummy resource if everyone did what you've done.
2. The answer you've got might be wrong. Surely getting some sort of 'peer review' of your answer is desirable.
3. Some members might have valuable contributions to make (like alternative methods of solution, interesting extensions to the original question etc.).
There are other reasons but these are the three most important, in my opinion anyway.