I don’t understand this. Can you please help me? thank you.

List the elements of the set in roster notation. (enter empty or ∅ for the empty set.) {x | x is a letter in the word hippopotamus}

Identify the type of observational study described. a statistical analyst obtains data about ankle injuries by examining a hospital's records from the past 3 years. cross-sectional retrospective prospective

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