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    Question

    (cot θ + tan θ)(cosec θ − sin θ)(cos θ − sec

    θ) = ________.
    B 1 Correct Answer Incorrect Answer
    C 2 Correct Answer Incorrect Answer
    D –1 Correct Answer Incorrect Answer

    Solution

    We start by simplifying each term individually: ⇒ cot θ + tan θ = (cos θ/sin θ) + (sin θ/cos θ) ⇒ = (cos2 θ + sin2 θ) / (sin θ cos θ) ⇒ = 1 / (sin θ cos θ)            [since cos2 θ + sin2 θ = 1] Next, simplify cosec θ - sin θ: ⇒ cosec θ - sin θ = (1/sin θ) - sin θ ⇒ = (1 - sin2 θ) / sin θ ⇒ = cos2 θ / sin θ            [since 1 - sin2 θ = cos2 θ] Finally, simplify cos θ - sec θ: ⇒ cos θ - sec θ = cos θ - (1/cos θ) ⇒ = (cos2 θ - 1) / cos θ ⇒ = -sin2 θ / cos θ            [since cos2 θ - 1 = -sin2 θ] Now, combine all three simplified terms: ⇒ (cot θ + tan θ)(cosec θ - sin θ)(cos θ - sec θ) ⇒ = (1 / (sin θ cos θ)) × (cos2 θ / sin θ) × (-sin2 θ / cos θ) ⇒ = (1 / (sin θ cos θ)) × (cos2 θ / sin θ) × (-sin2 θ / cos θ) ⇒ = (-1)    [After simplifying the terms and canceling out common factors] ∴ The expression equals -1.

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