How do I get from #2 to #3 in this trigonometry identity problem?

[jkristia]

I'm working on some trigonometry identity problems, and I'm stuck on this particular problem.
This is how it is shown in the solution, but I cannot see how to get the highlighted part.
Any help on how to get from #2 to #3 (the highlighted) is very much appreciated

Jesper

 

[Char. Limit]

Try multiplying the equation by 1. Or in this case, multiplying the numerator and denominator by sin(A) (which is equivalent to multiplying by 1).

 

[jkristia]

ahhh - of course, thank you very much for the quick help.