More recently, the discovery and exploitation of electricity and electromagnetic waves introduced exciting and very powerful new applications of the trigonometric functions. Indeed, of all the applications of classical mathematics, this is possibly one of the most profound and world changing. The trigonometric functions give the key to understanding and using wave motion and manipulating signals in communications. Decomposing signals into combinations of trigonometric functions is known as Fourier analysis. We will then look at trigonometric expansions, which will be very important in the later module The calculus of trigonometric functions. All this is best done, initially, using angles measured in degrees, since most students are more comfortable with these units. Finally, we conclude with a section on graphing the trigonometric functions, which illustrates their wave-like properties and their periodicity.
https://www.youtube.com/watch?v=snHKEpCv0Hk
Isn't this angle radian-t?Trig or treat!The unit circle (and the special right triangles)The sine and cosine functionsGeneral sine and cosine functionsThe tangent functionGraphing all six trigonometric functionsAlgebra with trigonometric functionsSolving trigonometric equationsFlip me over and call me a reciprocalInverse trigonometric functionsCan trig get harder?Sum and difference of anglesHalf angle and double angle identitiesTrigonometric models (real life applications)Solving for trig