The document discusses four math problems involving trigonometric identities, permutations, logarithms, and conic sections. Specifically, it provides worked examples to: 1) Prove a trigonometric identity by using double angle identities and reducing both sides of the equation. 2) Calculate the number of possible concert schedules that can be created from a list of provinces using permutations. 3) Determine which used car dealer offers the cheapest Honda Civic after 3 years of depreciation by using logarithms. 4) Derive the equations of an ellipse and parabola that can model a tunnel arch and determine which model more closely approximates the actual height at a given point.