For part two the relation between the two is both angles add to 360 or 2pi, since the line drawn is above the centre point y = 2 of the entire graph, meaning that the equation leads to cos x = positive number which makes x be in the first or the fourth quadrant, which is related by alpha and 360 - alpha where alpha is a basic angle.

Will write this up by 3 am if no one has done them yet.