Hey guys, Im really stumped on a revision paper I am doing for homework, if you could help me come to the answer I would appreciate it.

Given that cos x = (3^.5) − 1, find the value of cos 2x in the form a + b(3^.5) ,

where a and b are integers.

Given that

2 cos (y + 30)= 3 sin (y − 30),

find the value of tan y in the form k 3 where k is a rational constant.