Home
Class 12
MATHS
Prove that "cos" (3pi)/13 + "cos" (5pi)...

Prove that
`"cos" (3pi)/13 + "cos" (5pi)/13 - 2 "cos" (9pi)/13 "cos" (12pi)/13 = 0`

Promotional Banner

Topper's Solved these Questions

  • TRANSFORMATIONS OF SUMS AND PRODUCTS

    CHHAYA PUBLICATION|Exercise Long Answer Type Questions|16 Videos

  • TRANSFORMATIONS OF SUMS AND PRODUCTS

    CHHAYA PUBLICATION|Exercise Multiple Correct Answers Type|5 Videos

  • TRANSFORMATIONS OF SUMS AND PRODUCTS

    CHHAYA PUBLICATION|Exercise Very Short Answer type Questions|14 Videos

  • TANGENT AND NORMAL

    CHHAYA PUBLICATION|Exercise ASSERTION-REASON TYPE|2 Videos

  • TRIGONOMETRIC INVERSE CIRCULAR FUNCTIONS

    CHHAYA PUBLICATION|Exercise sample questions for competive examination|20 Videos

Similar Questions

Explore conceptually related problems

Prove that, 16 "cos" (2pi)/15 "cos" (4pi)/15 "cos" (8pi)/15 "cos" (16pi)/15 =1

Prove that "cos" (2pi)/15 cdot "cos"(4pi)/15 cdot "cos" (8pi)/15 "cos"(14pi)/15=1/(16)

Prove that, "cos" pi/11 "cos" (2pi)/11 "cos" (3pi)/11 "cos" (4pi)/11 "cos" (5pi)/11 = 1/32

Prove that, (1 + "cos" pi/8)(1 + "cos" (3pi)/8)(1 + "cos" (5pi)/8)(1 + "cos" (7pi)/8 ) = 1/8

2 cos ""pi/13 cos "" (9pi)/( 13) + cos "" (3pi)/(13) + cos " (5pi)/( 13) =0

"Show that : " "cos" pi/11 +"cos"(3pi)/11+ "cos" (5pi)/11+ "cos" (7pi)/11+"cos" (9pi)/11 =1/2 .

Prove that (1+"cos" (pi)/10)(1+"cos"(3pi)/10)(1+"cos"(7pi)/10)(1+"cos"(9pi)/10)=1/16 .

Prove that 8"cos"^3pi/9-6"cos"pi/9=1

Prove that "cos"^(8) (pi)/(8)+ "cos"^8 (3pi)/(8)+"cos"^(8) (5pi)/(8)+"cos"^(8)(7pi)/(8)=(17)/(16) ,

Prove that cos ((pi)/(4) + x) + cos ((pi)/(4) -x) = sqrt2 cos x

CHHAYA PUBLICATION-TRANSFORMATIONS OF SUMS AND PRODUCTS-Short Answer Type Questions
  1. Prove that sin19^(@) + sin41^(@) + sin83^(@) = sin23^(@) + sin37^(@) ...

    Text Solution

    |

  2. Prove that sin10^(@) + sin20^(@) + sin 40^(@) + sin 50^(@) = sin 70^(...

    Text Solution

    |

  3. Prove that "cos" (3pi)/13 + "cos" (5pi)/13 - 2 "cos" (9pi)/13 "cos" (...

    Text Solution

    |

  4. Prove that 4 sin 15^(@) sin 75^(@) = sqrt2 ( cos105^(@) + sin 75^(@)...

    Text Solution

    |

  5. Prove that sin 80^(@) cos20^(@) + sin45^(@) cos145^(@)+sin 55^(@) co...

    Text Solution

    |

  6. Prove that cos32^(@) sin20^(@) + cos144^(@) cos2^(@) + sin68^(@) cos...

    Text Solution

    |

  7. Prove that cos306^(@) + cos234^(@) + cos162^(@) + cos18^(@) = 0

    Text Solution

    |

  8. Prove that cos 10^(@) cos20^(@) + sin 45^(@) cos145^(@) + sin 55^(@)...

    Text Solution

    |

  9. Prove that cos24^(@) + cos 55^(@) + cos125^(@) +cos204^(@) + cos300^...

    Text Solution

    |

  10. Prove that cos20^(@) cos40^(@) cos80^(@) = 1/8

    Text Solution

    |

  11. Prove that 8 sin20^(@) sin40^(@) sin80^(@) = sqrt3

    Text Solution

    |

  12. Prove that tan20^(@) tan40^(@) tan80^(@) = sqrt3

    Text Solution

    |

  13. Prove that cos40^(@) cos80^(@) cos160^(@) = -1/8

    Text Solution

    |

  14. Prove that cos thetacos(60^(@)- theta)cos(60^(@)+theta) = 1/4 cos 3 ...

    Text Solution

    |

  15. Prove that 4 sin theta sin(pi/3 + theta) sin (pi/3-theta) = sin 3 th...

    Text Solution

    |

  16. Prove that cos alpha cos (120^(@) + alpha) cos (240^(@) + alpha) = 1...

    Text Solution

    |

  17. Find the value: sin 78^(@) - sin18^(@) + sin 30^(@) - sin42^(@)

    Text Solution

    |

  18. Find the value: sec20^(@) sec40^(@) sec80^(@)

    Text Solution

    |

  19. Find the value: sqrt3 cot20^(@) cot40^(@)cot80^(@)

    Text Solution

    |

  20. Find the value: 1/(2sin 10^(@))-2 sin 70^(@)

    Text Solution

    |