Copyright © University of Cambridge. All rights reserved.

## 'Sine and Cosine' printed from http://nrich.maths.org/

The Flash "movie" allows students to see the flow of function
values as the dot circles the centre point or origin. Students can
be encouraged to see the "spot" values provided by a calculator as
snap-shots of this flow.

Check that students grasp that an angle of zero is when the dot
is at (1,0), that the red line corresponds to the Sine value and
the blue line to the Cosine value.

There may be a need to guide students into noticing that there is a
the change of sign, and noticing when it occurs.