I figured I would post this in here and hopefully get somebody who likes trig to help me through this.

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.

a bit of background here is that I am looking to take my high school maths certificate and I found out that well... Im rubbish at trig!