Home
Class 12
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`

Promotional Banner

Topper's Solved these Questions

  • Circular Functions, Identities

    A DAS GUPTA|Exercise Exercise|300 Videos

  • Circles

    A DAS GUPTA|Exercise EXERCISE|122 Videos

  • COMPLEX NUMBERS

    A DAS GUPTA|Exercise EXERCISE|224 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

A DAS GUPTA-Circular Functions, Identities -Exercise
  1. Prove that cos^(4)pi/8+cos^(4)(3pi)/(8)+cos^(4)(5pi)/8+cos^(4)(7pi)/...

    Text Solution

    |

  2. Prove that tan 9^circ - tan 27^circ -tan 63^circ + tan 81^circ = 4.

    Text Solution

    |

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

    Text Solution

    |

  4. Prove that cos theta* cos 2theta* cos2^(2)theta * cos2^(3)theta x... ...

    Text Solution

    |

  5. Prove that cos pi/15 * cos 2pi/15* cos3pi/15... . . to 7 factors = 1...

    Text Solution

    |

  6. Prove that sin pi/14* sin 3pi/14* sin 5pi/14........... to 7 factors ...

    Text Solution

    |

  7. If A gt 0, B gt 0 and A + B = pi/3 then find the maximum value of tan...

    Text Solution

    |

  8. Find the minimum value of 9tan^(2)theta + 4cot^(2)theta.

    Text Solution

    |

  9. Show that the maximum and minimum values of sqrt(a^(2)cos^(2)theta + ...

    Text Solution

    |

  10. Find the set of possible values of (tan(x + pi/6))/tan x where x is an...

    Text Solution

    |

  11. Prove that for real x, (tan(x+alpha))/(tan(x-alpha)) where alpha ne pi...

    Text Solution

    |

  12. Show that (sec^(2)theta - tan theta)/(sec^(2)+ tan theta) lies betwe...

    Text Solution

    |

  13. Prove that tan alpha + 2tan 2alpha + 4tan 4alpha + 8cot 8alpha = cot ...

    Text Solution

    |

  14. Find the sum: tan x + 1/2 tan x/2+ 1/2^(2) tan x/2^(2) +.....+1/2^(n-...

    Text Solution

    |

  15. Prove that cosec 2alpha = cot alpha - cot 2alpha. Hence or otherwise ...

    Text Solution

    |

  16. Prove that sum(r=1)^(10) = sin^(2) rpi/18 =5.

    Text Solution

    |

  17. Sum the series: sin alpha - sin 2alpha + sin 3alpha - sin 4alpha + .....

    Text Solution

    |

  18. Find sum(r=1)^(10) cos^(3) rpi/3.

    Text Solution

    |

  19. Sum: sqrt(1 + sin 2alpha) + sqrt(1 + sin 4alpha) + sqrt(1 + sin 6alpha...

    Text Solution

    |

  20. Prove that sin^(2) 12^circ + sin^(2)21^circ + sin^(2)39^circ + sin^(2)...

    Text Solution

    |