- Both angles in one turn
- Every solution: add the period
- Isolate first, flip reciprocals
- List the solutions inside
- Count first, check the ends
- Solutions in degrees
- Substitute u for the inside
- Phase shifts
- Isolate, substitute, divide
- Factor, never divide
- Rewrite with an identity
- Check and reject
- When does the model reach a level
- Keep only the times that fit
- Values outside the range
- Unlocks after
- Opens up