The attached might help a little, though something is still not right as I don't get exactly the same result for equation (8). Because of that I haven't taken it any further - I'll leave you to figure out why!
Alan
The attached might help a little, though something is still not right as I don't get exactly the same result for equation (8). Because of that I haven't taken it any further - I'll leave you to figure out why!
Alan