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!)