**Sheri, a 5th grader, begins trig**

This is a 12 point circle. All of the points are 30 degrees

apart. Then Mr. Cohen added the points at 45' around. Each of them are equal to one other point on the circle.

All of these are equal to each other:

[Sheri measured the lengths of the segments for the sines of 30', 45', and 60', then found the ratios of these to the measured distance for 90' and came out very close to the calculator values in the table below for sin x.]

I graphed y=sin x, then found the equation for the graph to be twice as tall ( y= 2 sin x); I multiplied each sine value by 2".

Don went over things like 2x.7 = 1.4 which Sheri wasn't sure
about. But it was her idea to double sin x to get the equation of the graph to
be twice as tall. **Fine job Sheri!**

Mathman home