2. A – an expression to simplify C – an equation that is sometime true B – an equation that is never true D – an equation that is always true – an identity C A D B

4. 2 Cosine are the fingers left on top Sine are the fingers left on bottom Whatever angle you are dealing with, pull that finger back in.

5. Use inverse operations to solve each equation on the interval

7. Simplify each side of the equation, then solve on the interval Sometimes, when multiplying or dividing by an expression on both sides of an equation, extraneous solutions can be introduced. Be sure to check your final solutions.

8. Simplify each side of the equation, then solve on the interval

10. Set one side of the equation equal to zero; then factor to solve on the interval Solving tips: Always look for a common factor first. If no common factor is present, you may have to use an identity to rewrite the expression in terms of one function – using the same trig function or argument. Then you can factor into two parentheses.

11. Set one side of the equation equal to zero; then factor to solve on the interval