Home
Class 14
MATHS
Prove that cos^(4)pi/8+cos^(4)(3pi)/(8...

Prove that
`cos^(4)pi/8+cos^(4)(3pi)/(8)+cos^(4)(5pi)/8+cos^(4)(7pi)/8=3/2`

A

`(3)/(2)`

B

`(-2)/(3)`

C

1

D

`-1`

Text Solution

Verified by Experts

The correct Answer is:
B, C
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRY

    ADVANCED MATHS BY ABHINAY MATHS ENGLISH|Exercise EXERCISES (Multiple Choice Questions)|350 Videos

  • TIME, SPEED & DISTNACE

    ADVANCED MATHS BY ABHINAY MATHS ENGLISH|Exercise QUESTIONS|108 Videos

Similar Questions

Explore conceptually related problems

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

Prove that: cos^(4)(pi)/(8)+cos^(4)(3 pi)/(8)+cos^(4)(5 pi)/(8)+cos^(4)(7 pi)/(8)=(3)/(2)

Prove that sin^(4) pi/8+ sin^(4) 3pi/8 + sin^(4) 5pi/8 + sin^(4) 7pi/8 = 3/2 .

Prove that cos((pi)/(8))+cos((3 pi)/(8))+cos((5 pi)/(8))+cos((7 pi)/(8))=0

The value of sin^(4)(pi/8)+cos^(4)((3 pi)/8)+sin^(4)((5pi)/8)+cos^(4)((7pi)/8) is equal to =

Prove that cos((2pi)/7) cos((4pi)/7) cos((8pi)/7) =1/8

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

ADVANCED MATHS BY ABHINAY MATHS ENGLISH-TRIGONOMETRY -EXERCISES (Multiple Choice Questions)
  1. Let alpha, beta be such that pi lt alpha -beta lt 3 pi. If sin alpha...

    Text Solution

    |

  2. If 8cos2theta+8sec2theta=65and0^(@)ltthetalt(pi)/(2), then 4cos4theta ...

    Text Solution

    |

  3. Prove that cos^(4)pi/8+cos^(4)(3pi)/(8)+cos^(4)(5pi)/8+cos^(4)(7pi)/...

    Text Solution

    |

  4. cos""(pi)/(15).cos""(2pi)/(15).cos""(4pi)/(15).cos""(8pi)/(15) is equa...

    Text Solution

    |

  5. Find the value of:(1+cos""(pi)/(8))(1+cos""(3pi)/(8))(1+cos""(5pi)/(8)...

    Text Solution

    |

  6. If x=ycos""(2pi)/(3)=zcos""(4pi)/(3), then xy+yz+zx is equal to

    Text Solution

    |

  7. If A,Bin(0,pi//2),sinA=(4)/(5)andcos(A+B)=-(12)/(13), then sinB=?

    Text Solution

    |

  8. If a sectheta+b tantheta=1anda^(2)sec^(2)theta-b^(2)tan^(2)theta=5, th...

    Text Solution

    |

  9. Prove that sin^(4) pi/8+ sin^(4) 3pi/8 + sin^(4) 5pi/8 + sin^(4) 7pi/8...

    Text Solution

    |

  10. If alpha is acute angle and 2sin^(2)alpha+15cos^(2)alpha=7, then cotal...

    Text Solution

    |

  11. If 3xsintheta+2ycostheta=4and2xsintheta-3ycostheta=2, then relation be...

    Text Solution

    |

  12. If sintheta+costheta=aandsectheta+cosectheta=b, then the value of b(a^...

    Text Solution

    |

  13. If a sectheta+b tantheta=1anda^(2)sec^(2)theta-b^(2)tan^(2)theta=5, th...

    Text Solution

    |

  14. If (sec^(4)alpha)/(sec^(2)beta)-(tan^(4)alpha)/(tan^(2)beta)=1 where a...

    Text Solution

    |

  15. If (cos^(4)alpha)/(cos^(2)beta)+(sin^(4)alpha)/(sin^(2)beta)=1 then (c...

    Text Solution

    |

  16. 7cosectheta+24sectheta=25cosecthetasectheta, then costheta=?

    Text Solution

    |

  17. If 8sectheta+6cosectheta=20, then cottheta=?

    Text Solution

    |

  18. The numerical value of cos 2pi/7 + cos 4pi/7 + cos 6pi/7 is=........

    Text Solution

    |

  19. cos15^(@)cos7""(1)/(2)""^(@).cos82""(1)/(2)""^(@)=?

    Text Solution

    |

  20. tan^(2)theta=1-e^(2), then sectheta+tan^(3)theta.cosectheta=?

    Text Solution

    |