Trig Identities

Lots of Proofs this unit! We start with simplifying practice and then jump in.

Note: We will be using the Demana book for most, but not all, of the assignments.

2/24   Trig Identity basics

          HW D p.410-411/3-60 by 3's, 69-73 odd

2/25   Simplifying for a solution

          HW D p.411-412/52-62, 75-82, 85

2/26   Proving Trig Identities

          HW D p.418/11-51 odd (45, 47 are tough, don't stress), 71, 80

2/28   Sum and Difference Formulas

          HW D p.425-427/3,5,7,13,17,21,27,29,31-35,37,43,45,47,48,52,55,73

3/03   Double Angle, Half Angle and Power Reducing Formulas

          CW B p.374/39-41, p.385/45, 47

          HW D p.432/3-30 by 3's, 39-45 odd, 53

3/04   Review and Extension Problems  CW Worksheet (answer key)

          HW B p.384-385/37, 51, 53 and p.390-391/23, 26-28

3/05   Review Packet (answer key) (Practice Test and Answer Key)
3/07   Start Polar Coordinates

3/10  Trig Identities Test

There are several resources to view proofs of the angle addition and angle subtraction identities.  Look them over and make sure you understand them.  You will be required to prove some of the basic identities on your test and the proofs of these identities require diagrams which may not occur to you during a test situation if you haven’t thought about them before.

Demana Precalculus 5.3 page 421 (a distance formula based proof)

Brown Advanced Math 10.1 p.369 (a law of cosines based proof)

Mr. Richardson’s PowerPoint presentation

            download here

Another website with very elegant triangle proofs:

            http://www.cut-the-knot.org/triangle/SinCosFormula.shtml  and

            http://www.cut-the-knot.org/triangle/SinCosFormula2.shtml (beautiful!)

Geometric Trig

Post-test homework was to do the area and identity worksheet. We continue with the more geometric applications of trigonometry. For this unit we will use primarily the Brown book.

2/03  9.2  Area Formula and applications

                HW p.342-344/1-19 odd, 20-22, 35, 36

                (p.344/34 is a bonus problem - turn it in for extra credit)

2/04  9.3  Law of Sines

                HW p.347-349/1-27 odd

2/05  9.4  Law of Cosines (Snow Day, E-Block read Brown p.350-352, give the HW a try)

                HW p.352-354/1-17 odd, 22

2/07  9.1 - 9.4  Mixed Trig Problems  (I will be out taking a course - day 3, last day)

                HW p.337/31-33, 37;  p.349/28;  p.354/23 and p.356-358/11,14,18,21,24,25

2/10  9.4  Mixed Trig Problems

                HW p.357-358/29-37

2/11  9.4  Mixed Trig Problems

                HW p.358/38, 39, 40, 42

2/12  Review and Extension Problems (Worksheet and answer key) (Practice Test and Answer Key)
2/13  Half-Day due to snow, no G-Block, see links to extension worksheet above

2/14  Test of Geometric Trig

The Geometric Trig test will have questions that require a full understanding of the trig area formula, the Law of Sines, and the Law of Cosines. There will be two problems (chosen by me) from the "C" problems on page 358 (not 41 or 43). I have not assigned every problem in the unit but notice that after you finish these problems you should be able to find the area, the sides, the angles, the length of the median/angle bisector/altitude, and the radii of the inscribed and circumscribed circles for any triangle - among other things.

2/15-2/23  February Break