Home
Class 12
MATHS
The value of cos""(pi)/(11)+cos""(3pi)/(...

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

A

0

B

1

C

`1//2`

D

`-1//2`

Text Solution

Verified by Experts

The correct Answer is:
C
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • TRIGONOMETRY

    BITSAT GUIDE|Exercise BITSAT Archives|41 Videos

  • THREE DIMENSIONAL GEOMETRY

    BITSAT GUIDE|Exercise BITSAT ARCHIVES |11 Videos

  • VECTOR ALGEBRA

    BITSAT GUIDE|Exercise BITSAT Archives|21 Videos

Similar Questions

Explore conceptually related problems

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

cos(pi)/(11)+cos(3 pi)/(11)+cos(5 pi)/(11)+cos(7 pi)/(11)+cos(9 pi)/(11)=(1)/(2)

Knowledge Check

  • The value of cos""(pi)/(9)cos""(2pi)/(9)cos""(3pi)/(9), is

    A
    `1//8 cos20`
    B
    `-1//8`
    C
    1
    D
    0

  • The value of cos""(pi)/(9)cos""(2pi)/(9)cos""(3pi)/(9)cos""(4pi)/(9), is

    A
    `1/8`
    B
    `1/16`
    C
    `1/64`
    D
    `1/4`

  • The value of 2"cos"(pi)/(13)"cos"(9pi)/(13)+"cos"(3pi)/(13)+"cos"(5pi)/(13) is

    A
    `(1)/(2)`
    B
    0
    C
    `-(1)/(2)`
    D
    `(1)/(8)`

    • Similar Questions

    Explore conceptually related problems

    The value of 2(cos pi/11 + cos(3pi)/11 + cos(5pi)/11 + cos(7pi)/11 + cos(9pi)/11) is……….

    cos""(pi)/(7)+cos""(2pi)/(7)+cos""(3pi)/(7)+......cos""(6pi)/(7)=?

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

    The value of sin""(pi)/(14).sin""(3pi)/(14).sin""(5pi)/(14).sin""(7pi)/(14).sin""(9pi)/(14).sin""(11pi)/(14).sin""(13pi)/(14) is

    The value of cos "" (pi)/( 15) cos "" (2pi )/( 15)cos "" ( 3pi )/( 15)cos"" ( 4pi )/( 15)cos "" ( 5pi )/( 15) cos ""( 6pi)/( 15)cos "" ( 7 pi )/( 15) is

    Home
    Profile