8th question plssss helpp.....

Dear Student

\sin (β - γ) \cos (α - δ) + \sin (γ - α) \cos (β - δ) + \sin (α - β) \cos (γ - δ) \Rightarrow (\sin β \cos γ - \cos β \sin γ) (\cos α \cos δ + \sin α \sin δ) + (\sin γ \cos α - \cos γ \sin α) (\cos β \cos δ + \sin β \sin δ) + (\sin α \cos β - \cos α \sin β) (\cos γ \cos δ + \sin γ \sin δ) \Rightarrow [\sin β \cos α \cos γ \cos δ] - (\cos β \sin γ \cos α \cos δ) + \sin β \cos γ \sin α \sin δ - \{\sin α \cos β \sin γ \sin δ\} + (\sin γ \cos α \cos β \cos δ) - \sin γ \cos α \cos β \cos δ + (\sin γ \cos α \sin β \sin δ) - s i n β s i n δ c o s γ s i n α + \sin α \cos β \cos γ \cos δ - [\cos α \sin β \cos γ \cos δ] + \{\sin α \cos β \sin γ \sin δ\} - (\cos α \sin β \sin γ \sin δ) C a n c e l l i n g t e r m s i n d i f f e r e n t b r a c k e t s . W e w i l l g e t \sin (β - γ) \cos (α - δ) + \sin (γ - α) \cos (β - δ) + \sin (α - β) \cos (γ - δ) = 0

Regards