The value of cosπ15cos2π15cos4π15cos8π15 from M

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 Multiple Choice QuestionsMultiple Choice Questions

701.

The smallest value of 5cosθ + 12 is

  • 5

  • 12

  • 7

  • 17


 Multiple Choice QuestionsShort Answer Type

702.

Show that

sinθcos3θ + sin3θcos9θ + sin9θcos27θ = 12tan27θ - tanθ


 Multiple Choice QuestionsMultiple Choice Questions

703.

The equation 3sinx + cosx = 4 has

  • infinitely many solutions

  • no solution

  • two solutions

  • only one solution


704.

The value of

tanα + 2tan2α + 4tan4α + ... + 2n - 1tan2n - 1α + 2ncot2nα is

  • cot2nα

  • 2ntan2nα

  • 0

  • cotα


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705.

If tanαπ4 = cotβπ4, then

  •  α + β = 0

  •  α + β = 2n

  •  α + β = 2n + 1

  •  α + β = 2(2n + 1),  n is an integer


706.

The principal value of sin-1tan- 5π4 is

  • π4

  • π4

  • π2

  • - π2


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707.

The value of cosπ15cos2π15cos4π15cos8π15

  • 116

  • - 116

  • 1

  • 0


B.

- 116

cosπ15cos2π15cos4π15cos8π15= 142cos4π15cosπ152cos8π15cos2π15= 14cos60° + cos36°cos120° + cos72°= 1412 + 5 + 14- 12 + 5 - 14                cos36° = 5 + 14 and cos72° = 5 - 14= 14- 14 + 125 - 14 - 5 + 14 + 5 - 116= 1412- 12 = - 116


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708.

The principal amplitude of sin40° + icos40°5

  • 70°

  • - 110°

  • 110°

  • - 70° 


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 Multiple Choice QuestionsShort Answer Type

709.

Find the general solution of secθ + 1 = 2 + 3tanθ


 Multiple Choice QuestionsMultiple Choice Questions

710.

The real part of 1 - cosθ + 2isinθ- 1

  • 13 + 5cosθ

  • 15 - 3cosθ

  • 13 - 5cosθ

  • 15 + 3cosθ


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