If 2x = sec A and 2/x = tan A, prove that 
.
Given: 2x = sec A, and 2/x = tan A
Consider 2(x2 – (1/ x2))
= 
= 
= (1/2) [sec2 A – tan2 A]
= (1/2)[1]
= 1/2 (∵ sec2 x – tan2 x = 1)
6
If 2x = sec A and 2/x = tan A, prove that .
Given: 2x = sec A, and 2/x = tan A
Consider 2(x2 – (1/ x2))
=
=
= (1/2) [sec2 A – tan2 A]
= (1/2)[1]
= 1/2 (∵ sec2 x – tan2 x = 1)