If x = cot A + cos A and y = cot A - cos A, prove that
(x−yx+y)2+(x−y2)2=1.
x=cot A + cos A and
y=cot A − cos A
Now,
x + y= cot A + cos A + cot A − cos A = 2 cot A
x − y = cot A + cos A − cot A + cos A = 2 cos A
LHS = (x−yx+y)2+(x−y2)2
=(2cosA2cotA)2+(2cosA2)2
=(cosA×sinAcosA)2+(cosA)2
=sin2A+cos2A =1=RHS