One of the problems with a “live demonstration” is that when you drag the triangle, the numbers flash by quickly. You only see the numbers and the triangle for your current angle. This makes it difficult to see any pattern in the numbers. Making a list of the values, like the one below, doesn’t help much either:
Angle in Degrees sine cosine 0 0.000000 1.000000 1 0.017452 0.999848 2 0.034899 0.999391 3 0.052336 0.998630 4 0.069756 0.997564 5 0.087156 0.996195 6 0.104528 0.994522 7 0.121869 0.992546 8 0.139173 0.990268 9 0.156434 0.987688 10 0.173648 0.984808 11 0.190809 0.981627 12 0.207912 0.978148 13 0.224951 0.974370 14 0.241922 0.970296 15 0.258819 0.965926
Other than the fact that sine increases and cosine decreases, the pattern certainly doesn't leap out at you. To see the pattern more clearly, we will use a device called a strip chart recorder, shown below.
A strip chart is a long roll of paper that slides along underneath a movable pen. As the pen moves, it leaves a trail on the paper. You can start the strip chart rolling by clicking the Start button. The pen is attached to the vertical black line at the right edge of the paper roll. As you drag the pen up and down, you'll see the trail it leaves.