Problem:
Graphically investigate the function

with a = 0 and for various values of x between 0 and 2p.
Visualization:
The following is an animation of such an investigation using the program
Microcalc.

[Press here to see animation again!]
The animation shows the area bounded by the thin yellow line which is the
graph of y = sin(t), the t-axis, and the line t=x
for various increasing values of x. The thick yellow line is the
graph of y = F(x), the area function.