World Files - Defining Image Rotation

[Fawcett, David]

After spending a lot of time with my friend Google, I have come to the conclusion that documentation on how to calculate the rotation parameters of a world file is very hard to find.  

I have an image that I would like to georeference and rotate using a world file.  If I want to rotate the image 43 degrees counter-clockwise, how do I go about calculating the rotation parameters in the world file?  

Here are the params that I have already determined

0.177959962	pixel size x direction
                rotation x term
	        rotation y term
0.177941345	pixel size y direction
583930.6469	ul xcoord
4895626.67	ul ycoord

Thanks, 

David.