Which of the following does not represent a function of x

Based on the diagram, match the trigonometric ratios with the corresponding ratios of the sides of the triangle. tiles : cosb sinb tanb sincposs matches: c/b b/a b/c c/a

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

Find the area of the region between a regular hexagon with sides of 6" and its inscribed circle.