1. Math 120: Pre-calculus 2 Instructor: Mike Panitz (mpanitz@cascadia.ctc.edu)

2. Math 120: Pre-Calculus 2!2 Today Sum & Difference Formulas –Section (7.4 / 4e (9.4 / 3e)) Double & Half-Angle Formulas: –Section (7.5 / 4e (9.5 / 3e)) Exam #1 Review

3. Math 120: Pre-Calculus 2!3 Next Lecture Sum-to-Product/Product-To-Sum Formulas –Section (7.6 / 4e (9.6 / 3e)) Trig Equations: –Section (7.7-7.8 / 4e (9.7-9.8 / 3e))

4. Math 120: Pre-Calculus 2!4 Homework All homeworks will be collected on the day of the next exam (Feb 22 nd ) –Collected at the beginning of class –Hand them in before you start the exam

5. Math 120: Pre-Calculus 2!5 End of lecture slides

6. Math 120: Pre-Calculus 2!6 Exam #1 Good, overall You now own it –Save it to study for exam #2, final from We’ll go over things I think people had trouble with –These are likely to show up on exam #2, final

7. Math 120: Pre-Calculus 2!7 Finding trig functions by identity –Do not draw a triangle – do this all algebraically –See Exam Prep #1 for an example solution –Make sure you know this, for Exam #2, final! –Complementary angles! Establishing an identity –NOT AN EQUATION!!

8. Math 120: Pre-Calculus 2!8 Amplitude/Period/Phase Shift –Phase shift is the amount the equation is shifted RIGHTWARDS by –Therefore, you’ll SUBTRACT that amount, in the equation Proving that Sin(45 or 30) is X: –Start with definition of sin, and that angle –Show how to get the appropriate special triangle –Then use the definition to get X

9. Math 120: Pre-Calculus 2!9 Question Redo Next Tuesday (Feb 14 th ) I’ll pick one or two questions from the exam –I’ll create a ‘quiz’ based on those questions –Not those questions exactly, but the questions will be similar (i.e., different numbers, different expression, etc) The quiz will count as “extra credit” points, to be added to your Exam #1 grade.