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  1. Value of sec² θ -
    sin² θ - 2sin 4 θ
    		 is
    2cos4θ - cos² θ
    1. 1
    2. 2
    3. - 1
    4. 0
Correct Option: A

sec²θ -
sin²θ - 2sin4θ
2cos4θ - cos²θ

sec²θ -
sin²θ (1 - 2sin²θ)
cos²θ(2cos²θ - 1)

sec²θ -
sin²θ (1 - 2(1 - 2sin²θ))
cos²θ(2cos²θ - 1)

sec²θ - tan²θ
(2 cos²θ - 1)
2 cos²θ - 1

= sec²θ - tan²θ = 1


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