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  1. If sin (90°– θ) + cosθ = 2 cos(90° – θ), then the value of cosecθ is
    1. 2
      3

    2. 3
      2

    3. 1
      2

    4. 1
      3
Correct Option: B

sin (90° – θ) + cosθ = √2cos (90° – θ)
⇒ cosθ + cosθ = √2sinθ
⇒ 2 cosθ = √2sinθ

cosθ
=
2
=
1
sinθ22

⇒ cotθ =
1
2

∴ cosec2θ = 1 + cot2θ
⇒ cosec2θ = 1 +
1
2
2

cosec2θ = 1 +
1
=
3
22

⇒ cosecθ = √
3
2



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