Formulas

We are still reviewing all our old test for the trig exam that is coming up, so I decided to show all the formulas we used for the review chapter 10 test.

1.  sin 2 theta= 2sin theta*cos theta
2.  cos2theta= cos^2theta-sin^2theta
3.  cos2theta=1-2sin^2theta
4.  cos2theta=2cos^2-1
5.  tan2theta=  2tan/1-tan^2theta
6.  sin theta/2=  +/- square root of 1-cos theta/2
7.  cos theta/2= +/- square root of 1+cos theta/2
8.  tan theta/2= +/-  square root of 1-cos theta/1+cos theta
9.  tan theta/2= +/-  sin theta/1+cos theta
10. tan theta/2= +/- 1-cos theta/sin theta
11. cos(theta +/- beta)= cos theta*cos beta-/+sin theta*sin beta
12. sin(theta+/- beta)= sin theta*cos beta+/- cos theta*sin beta
13. tan(theta+beta)= tan theta+tan beta/1-tan theta*tan beta
14. tan(theta-beta)= tan theta-tan beta/1+tan theta*tan beta