I have a game: QUAK that utilizes the SIN behavior like so:
<img src="http://quak.laurig.de/Unbenannt.JPG" border="0">
It now seems to me, that if you change the Y-coordinate it influences the magnitude?!
Try it by shooting at the bathtub till the water level is at the lowest, then shoot the faucet. Now the Ducks seem to "jump" more as befor...
Any ideas why this happens?