Trigonometry
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If π sinθ = 1, π cosθ = 1, then the value of √3tan 2 θ + 1 is 3
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πsin θ = 1 and πcos θ = 1
∴ πsin θ = 1 πcos θ
∴ tan θ = 1 = tan 45°
⇒ θ = 45°∴ √3tan 2 θ + 1 3 = √3tan 2 × 45° + 1 = √3 tan30° + 1 3 Required answer = √3 × 1 + 1 = 1 + 1 = 2 √3
Correct Option: C
πsin θ = 1 and πcos θ = 1
∴ πsin θ = 1 πcos θ
∴ tan θ = 1 = tan 45°
⇒ θ = 45°∴ √3tan 2 θ + 1 3 = √3tan 2 × 45° + 1 = √3 tan30° + 1 3 Required answer = √3 × 1 + 1 = 1 + 1 = 2 √3
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Find the value of 1 + 1 . 1 + tan2θ 1 + cot2θ
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Expression = 1 + 1 1 + tan2θ 1 + cot2θ Expression = 1 + 1 sec2θ cosec2θ
[ ∵ sec2θ - tan2θ = 1 , cosec2θ - cot2θ = 1 ]
Expression = cos2θ + sin2θ = 1
[ ∵ cosθ . secθ = 1 , sinθ . cosecθ = 1 ]
Correct Option: B
Expression = 1 + 1 1 + tan2θ 1 + cot2θ Expression = 1 + 1 sec2θ cosec2θ
[ ∵ sec2θ - tan2θ = 1 , cosec2θ - cot2θ = 1 ]
Expression = cos2θ + sin2θ = 1
[ ∵ cosθ . secθ = 1 , sinθ . cosecθ = 1 ]
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If tanθ + 1 = 2 , then the value of tan2θ + 1 is equal to : tanθ tan2θ
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tanθ + 1 = 2 tanθ
⇒ tan2θ + 1 = 2tanθ
⇒ tan2θ - 2tanθ + 1 = 0
⇒ ( tanθ - 1 )2 = 0 ⇒ tanθ - 1 = 0
⇒ tanθ = 1∴ tan2θ + 1 = 1 + 1 = 2 tan2θ Correct Option: C
tanθ + 1 = 2 tanθ
⇒ tan2θ + 1 = 2tanθ
⇒ tan2θ - 2tanθ + 1 = 0
⇒ ( tanθ - 1 )2 = 0 ⇒ tanθ - 1 = 0
⇒ tanθ = 1∴ tan2θ + 1 = 1 + 1 = 2 tan2θ
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What is the value of (cotθ + cosecθ - 1) ? (cotθ - cosecθ + 1)
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Expression = (cotθ + cosecθ - 1) (cotθ - cosecθ + 1) Expression = cotθ + cosecθ - (cosec2θ - cot2θ) (cotθ - cosecθ + 1) Expression = (cotθ + cosecθ) - (cosecθ - cotθ)(cosecθ + cotθ) (cotθ - cosecθ + 1) Expression = (cotθ + cosecθ)(1 - cosecθ + cotθ) = cotθ + cosecθ (cotθ - cosecθ + 1) Correct Option: A
Expression = (cotθ + cosecθ - 1) (cotθ - cosecθ + 1) Expression = cotθ + cosecθ - (cosec2θ - cot2θ) (cotθ - cosecθ + 1) Expression = (cotθ + cosecθ) - (cosecθ - cotθ)(cosecθ + cotθ) (cotθ - cosecθ + 1) Expression = (cotθ + cosecθ)(1 - cosecθ + cotθ) = cotθ + cosecθ (cotθ - cosecθ + 1)
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If sinθ × cosθ = 1 .The value of sinθ – cosθ is where 0° < θ < 90° 2
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sinθ. cosθ = 1 2
⇒ 2 sinθ. cosθ = 1
⇒ sin2θ = 1 = sin 90°
⇒ 2θ = 90°
⇒ θ = 45°
∴ sinθ – cosθ = sin 45° – cos 45°sin 45° – cos 45° = 1 - 1 = 0 √2 √2 Correct Option: A
sinθ. cosθ = 1 2
⇒ 2 sinθ. cosθ = 1
⇒ sin2θ = 1 = sin 90°
⇒ 2θ = 90°
⇒ θ = 45°
∴ sinθ – cosθ = sin 45° – cos 45°sin 45° – cos 45° = 1 - 1 = 0 √2 √2