Wednesday, 26 November 2014

Double Angle Formulas

Started by using the compound angle formulas and replaced the second angle so it would be equal to the first. By doing this we were able to generate the double angle formulas for sin2A, cos2A, and tan2A. Here is some work from various groups.


 Then we looked at a few direct questions where I asked for the exact value but the angles were so that we did not have special triangles. So....groups needed to use the double angle formulas to rewrite the expression so that they did have a special triangle. 


Next example I gave the value of sin theta and cos theta as shown and asked for values for the other five expressions shown by using the double angle formulas.



Lastly we tried to find formulas for sin(3theta) in terms of sin(theta) only and cos(3theta) in terms of cos(theta) only. To do this we needed the compound formulas and the double angle formulas.



No comments:

Post a Comment