Trigonometry PROBLEM! (1 Viewer)

[whackymac]

This question 'popped' out while i was learning how to change sum into products. There seem to be no identities to this question.


Expressed this term in products.

1) sina - cosb


Need help on this question. Show the working out please

 

[lolokay]

change sina to cos(90-a) or cosb to sin(90-b)