PPT Slide
This Module concerns the CIRCULAR FUNCTIONS, so named because they were originally derived from the circle.
One way to think of these functions is of functions where the variable is an ANGLE. It turns out that these functions are extremely common - and are good approximations for many phenomena: for example waves, orbits, swings, pendulums and springs.
Their study is rewarding, and provides many more applications than the familiar right-angled triangle problems of school days.