Question

Question #c8582

Answer 1

Please refer to the Explanation.

Explanation:

Use the following Results

`sinx+siny=2sin((x+y)/2)cos((x-y)/2)`,

`cosx-cosy=-2sin((x+y)/2)sin((x-y)/2)`, to get the R.H.S.,

`-cot((alpha-beta)/2), or, cot((beta-alpha)/2)`.