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If cotθ + tanθ = 2cosecθ, then find the general value of θ.

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प्रश्न

If cotθ + tanθ = 2cosecθ, then find the general value of θ.

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उत्तर

Given that: cotθ + tanθ = 2cosecθ

⇒ `costheta/sintheta + sintheta/costheta = 2/sintheta`

⇒ `(cos^2theta + sin^2theta)/(sintheta cos theta) = 2/sintheta`

⇒ `1/(sintheta costheta) = 2/sintheta`

⇒ 2sinθ cosθ = sinθ

⇒ 2sinθ cosθ – sinθ = 0

⇒ sinθ(2cosθ – 1) = 0

⇒ sinθ ≠ 0 or 2cosθ – 1 = 0 or cosθ = `1/2`

⇒ cosθ = `cos  pi/3`

∴ θ = `2"n"pi +- pi/3`

Hence, the general value of θ is `2"n"pi +- pi/3`.

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अध्याय 3: Trigonometric Functions - Exercise [पृष्ठ ५४]

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एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 3 Trigonometric Functions
Exercise | Q 17 | पृष्ठ ५४

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