posted by kristen .
establish the identity:
thanks for any help at all
Is the final term
Is the numerator term (cotA cotB +1) or 1 ?
When you write equations like that, we can't tell what you mean.
I suggest you start with the identities for cos (A-B) and sin (A-B) and take the ratio of the two.
multiplying and dividing by sinasins then it becomes