The Cosine Curve
Hi there I would like to know how to do the following questions without drawing a graph. What is the formula?
The question: Express each of the following in terms of the cosine of another angle between 0° and 180°
a) cos 20°
b) cos 85°
Thank you for any help!
Originally Posted by Xine
There is no formula.
Treat the given angles as reference angles or use the symmetry of a unit circle.
If you have not been taught either of these concepts, let us know.
Cheers ~ Mark