Question

Cosec a + cos a = x find cosec a- cos a

Answer 1

X= cosec A+ cos A

y= cosec A - cos A

= x+y = 2 cosec A

= 2/(x+y)= sin A

(x-y)/2 = cos A

Lhs =[2/(x+y)2+ [(x-y)/2]2-1

= sin2 A+cos2 A-1

= 1-1=0