Home
Class 11
MATHS
(cos^4(pi/8))+(cos^4((3pi)/8))+(cos^4((5...

`(cos^4(pi/8))+(cos^4((3pi)/8))+(cos^4((5pi)/8))+(cos^4((7pi)/8))` is

Promotional Banner

Topper's Solved these Questions

  • STRAIGHT LINES

    CENGAGE PUBLICATION|Exercise All Questions|486 Videos

Similar Questions

Explore conceptually related problems

Find the value of (1+cos (pi/8))(1+cos(3pi/8))(1+cos(5pi/8))(1+cos(7pi/8))

Prove that cos^8(pi/8)+cos^8((3pi)/8)+cos^8((5pi)/8)+cos^8((7pi)/8)=17/16

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

Evaluate : cos^2(pi/8)+cos^2((3pi)/8)+cos^2((5pi)/8)+cos^2((7pi)/8)

Find the values: (iv) cos^(2) ((pi)/8) + cos^(2) ((3pi)/8) + cos^(2) ((5pi)/8) + cos^(2) ((7pi)/8)

Which of the following quantities are rational? (a) sin((11pi)/(12))sin((5pi)/(12)) (b) cos e c((9pi)/(10))sec((4pi)/5) (c) sin^4(pi/8)+cos^4(pi/8) (d) (1+cos((2pi)/9))(1+cos((4pi)/9))(1+cos((8pi)/9))

cos(pi/14) + cos ((3pi)/14) + cos((5pi)/14) =

The value of (1+ cos ""(pi)/(8))(1+cos""(3pi)/(8))(1+ cos ""(5pi)/(8)) (1+ cos "'(7pi)/(8)) is-

Prove that "cos"^(8) (pi)/(8)+ "cos"^8 (3pi)/(8)+"cos"^(8) (5pi)/(8)+"cos"^(8)(7pi)/(8)=(17)/(16) ,

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

CENGAGE PUBLICATION-TRIGONOMETRIC FUNCTIONS-All Questions
  1. If sinalpha+sinbeta=a and cosalpha+cosbeta=b , prove that tan((alpha...

    Text Solution

    |

  2. If tan(alpha/2)=sqrt((a-b)/(a+b)) tan(beta/2) prove that cosalpha=(aco...

    Text Solution

    |

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

    Text Solution

    |

  4. If pi < x < 2pi, prove that (sqrt(1+cosx)+sqrt(1-cosx))/(sqrt(1+...

    Text Solution

    |

  5. If f(x)=2(7cosx+24sinx)(7sinx-24cosx), for every x in R , then maximu...

    Text Solution

    |

  6. If costheta=cosalphacosbeta , prove that t a n(theta+alpha)/2t a n(th...

    Text Solution

    |

  7. Prove that sqrt(sin^4x+4cos^2x)-sqrt(cos^4x+4sin^2x)=cos2xdot

    Text Solution

    |

  8. If cos^2A+cos^2B+cos^2C=1, t h e n ABC is

    Text Solution

    |

  9. Number of triangles A B C if tanA=x ,tanB=x+1,a n dtanC=1-x is

    Text Solution

    |

  10. Which of the following quantities are rational? (a)sin((11pi)/(12))sin...

    Text Solution

    |

  11. If log(10)sin x + log(10)cos x=-1 and log(10)(sin x + cos x)=((log(10)...

    Text Solution

    |

  12. If tan(alpha-beta)=(sin2beta,)/(3-cos2beta) then (a)tanalpha=2tanbet...

    Text Solution

    |

  13. If cosbeta is the geometric mean between sinalphaa n dcosalpha, where ...

    Text Solution

    |

  14. In a triangle A B C , if A-B=120^0a n dsin(A/2)sin(B/2)sin(C/2)=1/(32...

    Text Solution

    |

  15. In a Delta PQR,angleR=pi/2. If tan(P/2) and tan (Q/2) are the roots of...

    Text Solution

    |

  16. If (tanx)/2=(tany)/3=(tanz)/5,x+y+z=pi and tan^2x+tan^2y+tan^2z is

    Text Solution

    |

  17. In A B C , if sin^3theta=sin(A-theta)sin(B-theta)sin(C-theta) , then ...

    Text Solution

    |

  18. If sin^(-1)a+sin^(-1)b+sin^(-1)c=pi, then the value of asqrt((1-a^2))+...

    Text Solution

    |

  19. Find the sum of the series cos e ctheta+cos e c2theta+cos e c4theta+ t...

    Text Solution

    |

  20. If tan6theta=p/q , find the value of 1/2(pcosec2theta-qsec2theta)

    Text Solution

    |