Question

urgent .. formula for sin -1 X + sin -1 Y , sin -1 X -sin -1 Y cos -1 X + cos -1 Y cos -1 X - cos -1 Y

Answer 1

Sin x + sin y=2sin (x+y)÷2 cos (x-y)÷2
Sin x - sin y=2cos (x+y)÷2 sin  (x-y)÷2
Cos x + cos y=2cos (x+y)÷2 cos (x-y)÷2
Cos x - cos y= -2sin (x+y)÷2 sin (x-y)÷2