I have following trig function:

X = COT^{-1}( -(TAN(A) * SIN(B) + SIN(Y) * COS(B)) ) / COS(Y) )

A and B are known as well as X. I need to solve it for Y.

I've tried to solve it already, and I have sinking feeling that it might be unsolvable.

If it helps, A is between -90 and 90 degrees inclusive. B equals to something close to 23.45 degrees, it's the obliquity of earth's ecliptic.

Thanks.