I want to check my answers, I feel that I did them correctly but I am questioning on how easy I got them. Thanks

1.If the terminal side of a 330 degree angle intersects a unit circle, what would the coordinates at the point of intersection?

Answer: {cos(30), -sin(30)} = {square root 3/2, -1/2}

2.Solve for x:3 + cos 2x = 7/2; only include answers on [0, 2]

Answer: first part : 2x=cos^-1(1/2)=pie/3 which is equal to 5pie/3 for the first part

second part: 2x=pie/6, 5pie/6, 7pie/6 and 11pie/6

sorry I could not figure out on how to put the pie symbol on this.

3- Verify the following identity by using an angle sum identity: cos (2x) = 1 - 2(sin²x).Hint (2x = x + x)

Answer: cos(2x) = cos² - sin²x = 1- sin² - sin² x = 1 - 2sin²x