Home
Class 11
MATHS
Show that "cos"(pi)/(15)"cos"(2pi)/(15)"...

Show that `"cos"(pi)/(15)"cos"(2pi)/(15)"cos"(3pi)/(15)"cos"(4pi)/(15)"cos"(5pi)/(15)"cos"(6pi)/(15)"cos"(7pi)/(15)=(1)/(128)`.

Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

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

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

Show that 16cos((2pi)/(15))cos((4pi)/(15))cos((8pi)/(15))cos((16pi)/(15))=1

Show that 16cos((2pi)/(15))cos((4pi)/(15))cos((8pi)/(15))cos((16pi)/(15)) =1

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

The value of cos""(pi)/(11)+cos""(3pi)/(11)+cos""(5pi)/(11)+cos""(7pi)/(11)+cos""(9pi)/(11), is

Find the value of cos^(-1)(cos""(pi)/(7)cos""(pi)/(17)-sin""(pi)/(7)sin""(pi)/(17))

Prove that cos^(2)""pi/8+cos^(2) ""(3pi)/(8)+cos^(2)""(5pi)/(8)+cos^(2)""(7pi)/(8)=2

FULL MARKS-SAMPLE PAPER 13-PART
  1. Given veca=2hati+2hatj+3hatk, vecb=-hati+2hatj+hatk and vecc=3hati+hat...

    Text Solution

    |

  2. Find the relation between a and b if lim(xto3)f(x) exists where f(x)={...

    Text Solution

    |

  3. Find the derivative of t^(3) cos t with respect to t.

    Text Solution

    |

  4. There are 15 candidates for an examination. 7 candidates are appearing...

    Text Solution

    |

  5. Find the largest possible domain for the real valued function f define...

    Text Solution

    |

  6. Resolve into partial fractions (3x+7)/(x^(2)-3x+2).

    Text Solution

    |

  7. Iff ""^(5)P(r)=""^(6)P(r-1) find r.

    Text Solution

    |

  8. Show that |{:(x,a,a),(a,x,a),(a,a,x):}|=(x+2a)(x-a)^2

    Text Solution

    |

  9. Find the unit vectors perpendicular to each of the vectors veca+vecb" ...

    Text Solution

    |

  10. Evaluate lim(xto3)(x^(2)-9)/(x-3) if it exists by finding f(3^(-)) and...

    Text Solution

    |

  11. Prove that the equations to the straight lines through the origin each...

    Text Solution

    |

  12. Evalute int(1)/(sqrt(x+3)-sqrt(x-4))dx.

    Text Solution

    |

  13. Prove that cos5theta=16cos^(5)theta-20cos^(3)theta+5costheta.

    Text Solution

    |

  14. Let A={1,2,3,4} and B={a,b,c,d}. Give a function from AtoB for each of...

    Text Solution

    |

  15. Show that "cos"(pi)/(15)"cos"(2pi)/(15)"cos"(3pi)/(15)"cos"(4pi)/(15)"...

    Text Solution

    |

  16. If x,y,z are respectively p^(th), q^(th) and r^(th) terms of a G.P sho...

    Text Solution

    |

  17. Three vectors veca,vecb and vecc are such that |veca|=2,|vecb|=3,|vecc...

    Text Solution

    |

  18. Suppose the chances of hitting a target by a person X is 3 times in 4 ...

    Text Solution

    |

  19. Evaluate lim(xtooo)((x^(2)-2x+1)/(x^(2)-4x+2))^(x)

    Text Solution

    |

  20. (a) If y=cos(msin^(-1)x) prove that (1-x^(2))y(3)-3xy(2)+(m^(2)-1)y(1)...

    Text Solution

    |