NDA Maths Mock Test – 01 – Q5

If f(α) = √(sec² α – 1), then what is (f(α) + f(β)) / (1 – f(α)f(β)) equal to?

• f(α + β)
• f(α – β)
• f(α) f(β)
• f(αβ)

‘
‘ Gi√en,
f(a) = √sec²a—1=tana
‘ Now, f(8) = √sec? B—1 =tanf ‘
We know that,
! F@)+£(8) _ tanottang !
i T7@7(b) _ 1 tanatanf
= tan(a + f)
‘ = /secz(a +B) —1= f(a+pB)
∞
1 (¢) (8,11), (10,13) 1
‘