Home
Class 12
MATHS
cis(pi)/(10).cis(2pi)/(10).cis(3pi)/(10)...

`cis(pi)/(10).cis(2pi)/(10).cis(3pi)/(10).cis(4pi)/(10)=`

A

1

B

-1

C

0

D

2

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • DEMOIVRE'S THEOREM

    AAKASH SERIES|Exercise EXERCISE -II|58 Videos

  • DEFINITE INTEGRALS

    AAKASH SERIES|Exercise Exercise (Level-2)|38 Videos

  • DIFFERENTIAL EQUATIONS

    AAKASH SERIES|Exercise Practice Exercise|62 Videos

Similar Questions

Explore conceptually related problems

sin(pi/10)sin((13pi)/10)=

The value of cos""(pi)/(7)+cos""(2pi)/(7)cos""(3pi)/(7)+cos""(4pi)/(7)+cos""(5pi)/(7)+cos""(6pi)/(7)+cos""(7pi)/(7) is

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

cos. (pi)/(7) + cos. (2pi)/(7) + cos. (3pi)/(7) + cos. (4pi)/(7) + cos. (5pi)/(7) + cos. (6pi)/(7)=

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

Show that cos^(2)""(pi)/(10)+cos^(2)""(4pi)/(10)+cos^(2)""(6pi)/10+cos^(2)""(9pi)/10=2 .

For A in R , prove that cos""pi/9.cos""(2pi)/9.cos""(3pi)/9.cos""(4pi)/9=1/16

tan. (pi)/(10) + tan. (3pi)/(10) + tan. (7pi)/(10) + tan. (9pi)/(10) =

Show that (1+"Cos"pi/10)(1+"Cos"(3pi)/10)(1+"Cos"(7pi)/10)(1+"Cos"(9pi)/10)=1/16 (AP March-2015,May-2015,TS May-2015)

AAKASH SERIES-DEMOIVRE'S THEOREM-PRACTICE EXERCISE
  1. If x=cisalpha,y=cisbeta" then " x^3y^4-(1)/(x^3y^4)=

    Text Solution

    |

  2. If a,b and c are in G.P then (b - a)/(b - c) + (b + a)/(b + c)

    Text Solution

    |

  3. cis(pi)/(10).cis(2pi)/(10).cis(3pi)/(10).cis(4pi)/(10)=

    Text Solution

    |

  4. If xn=cos(pi/2^n)+isin(pi/2^n), then x1 x2 x3......infinity

    Text Solution

    |

  5. If x(n)=cos((pi)/(4^(n)))+i sin ((pi)/(4^(n))), then x(1), x(2), x(3)....

    Text Solution

    |

  6. The continued product of the four values of (1-isqrt3)^(3//4) is

    Text Solution

    |

  7. The continued product of all values of root(5)(4) is

    Text Solution

    |

  8. sum(r=1)^(8)[sin(2pir//9)+icos(2pir//9)]=

    Text Solution

    |

  9. The values of sum(m=1)^(10)[sin(2pim//11)-icos(2pim//11)] is

    Text Solution

    |

  10. If cosalpha+cosbeta+cosgamma=0=sinalpha+sinbeta+singamma then sin3alph...

    Text Solution

    |

  11. If cos alpha+cos beta+cos gamma=0 & sin alpha +sin beta +sin gamma=0. ...

    Text Solution

    |

  12. If cos alpha+cosbeta+cosgamma = 0 = sinalpha + sinbeta + singamma then...

    Text Solution

    |

  13. If cosalpha+cosbeta+cosgamma=0=sinalpha+sinbeta+singamma then sin(2alp...

    Text Solution

    |

  14. If cosalpha+cosbeta+cosgamma=0=sin alpha+sinbeta+singamma then cos^2al...

    Text Solution

    |

  15. If cosalpha+coabeta+cosgamma=0=sinalpha+sinbeta+singamma then cos(alph...

    Text Solution

    |

  16. If a=cisalpha,b=cisbeta,c=cisgamma, and a/b+b/c+c/a-1=0 then cos(alph...

    Text Solution

    |

  17. If A+B+C= pi and cos A+cos B+cos C=0=sin A+sin B+sin C , then sin 3A+...

    Text Solution

    |

  18. The cube roots of 1+I are

    Text Solution

    |

  19. The values of (sqrt3+i)^(1//4) are

    Text Solution

    |

  20. The values of (1+i)^(2//3) are

    Text Solution

    |