Home
Class 11
MATHS
cos^(@)cos2^(@)cos3^(@).......cos179^(@)...

`cos^(@)cos2^(@)cos3^(@).......cos179^(@)=`

A

`(1)/(sqrt(2))`

B

0

C

1

D

-1

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMERTIC RATIOS

    AAKASH SERIES|Exercise EXERCISE- II|52 Videos

  • TRIGNOMETRIC EQUATIONS

    AAKASH SERIES|Exercise ADDITIONAL PRACTICE EXERCISE (PRACTICE SHEET (ADVANCED) INTEGER TYPE QUESTIONS)|2 Videos

  • TRIGONOMETRIC EQUATIONS

    AAKASH SERIES|Exercise Practice Exercise|49 Videos

Similar Questions

Explore conceptually related problems

cos 1^(@) + cos 2^(@) + cos 3^(@) + ... + cos 179^(@)=

cos^(2)1^(@)+ cos^(2)2^(@)+cos^(2)3^(@)+....+cos^(2)90^(@)=

A=cos 20^(@)cos 40^(@) cos60^(@)cos 80^(@) , B=cos6^(@)cos42^(@)cos66^(@)cos78^(@) and C=cos 36^(@)cos72^(@)cos 108^(@)cos 144^(@) then

The value of cos 1^@.cos 2^@.cos 3^@............cos 180^@ =………….

cos^(2)5^(@)+cos^(2)10^(@)+cos^(2)15^(@)+.....+cos^(2) 90^(@)=

Prove that cos^(2)76^(@)+cos^(2)16^(@)-cos76^(@)cos16^(@)=(3)/(4)

(cos^(3)21^(@)+cos^(3)39^(@))/(cos21^(@)+cos39^(@))=

cos^(2)25^(@)+cos^(2)35^(@)-cos25^(@) cos35^(@)=

Let x=sin1^(@) , then the value of the expression (1)/(cos 0^(@).cos 1^(@))+(1)/(cos 1^(@).cos 2^(@))+(1)/(cos 2^(@),cos3^(@))+……..+(1)/(cos 44^(@).cos45^(@)) is equal to

AAKASH SERIES-TRIGONOMERTIC RATIOS-PRACTICE EXERCISE
  1. Prove that sin^(2)5^(@) +sin^(2)10^(@) + sin^(2)15^(@)+...+sin^(2)90^(...

    Text Solution

    |

  2. cos^(2)5^(@)+cos^(2)10^(@)+cos^(2)15^(@)+.....+cos^(2) 90^(@)=

    Text Solution

    |

  3. cos^(@)cos2^(@)cos3^(@).......cos179^(@)=

    Text Solution

    |

  4. tan10^(@) tan 20^(@) tan 30^(@) tan 40^(@) tan 50^(@) tan 60^(@) tan 7...

    Text Solution

    |

  5. [(Tan ( pi - x) Tan (1.5 pi + x))/(Cos^(2)(x-1.5pi))-(Cos(1.5pi + x))/...

    Text Solution

    |

  6. If cos A = 3/4 then (2cos A + 3 sin A)/(4 cos A - sin A) =

    Text Solution

    |

  7. If theta is acute and (1-a^(2)) sin theta =(1+ a^(2)) cos theta , t...

    Text Solution

    |

  8. If cot theta=-3//4 and theta is not in the second quadrant , then ...

    Text Solution

    |

  9. If tan 20^(@) = lambda , " then " (tan 250^@ + tan 340^(@))/(tan 200^...

    Text Solution

    |

  10. 3(sin x + cos x )^(4) + 6(sin x - cos x )^(2) + 4(sin^(6) x + cos^(6) ...

    Text Solution

    |

  11. If k=( sec A + tan A) ( sec B+ tan B) sec C + tan C)=(sec A - tan A)(s...

    Text Solution

    |

  12. In Delta le ABC, 3 tan A+4=0 then the quadratic equation whose roots a...

    Text Solution

    |

  13. If sin theta , cos theta are ther roots of the equation ax^(2)-bx+c...

    Text Solution

    |

  14. If (x)/(a) cos theta + (y)/(b) sin theta = 1 , (x)/(a) sin theta - (y...

    Text Solution

    |

  15. If x = h + p Sec alpha, y = k + q cosec alpha then ((p)/(x-h))^(2) +((...

    Text Solution

    |

  16. If x=a("cosec" theta + cot theta ) , y=b( " cosec " theta - cot theta ...

    Text Solution

    |

  17. (1+cosec theta - cot theta)/(1+cosec theta + cot theta)=

    Text Solution

    |

  18. (1)/(sec^(4) alpha ) +(1)/("cosec"^(4) alpha ) +(2)/(sec^(2) alpha + ...

    Text Solution

    |

  19. ( cos^(3) A + sin^(3) A )/( cos A + sin A ) + (cos^(3) A - sin^(3)A)/(...

    Text Solution

    |

  20. If cosec theta + cot theta = 1//3 then cosec theta - cot theta =

    Text Solution

    |