Home
Class 11
MATHS
If Un=2 cosntheta then U1Un-U(n-1) is eq...

If `U_n=2 cosntheta` then `U_1U_n-U_(n-1)` is equal to

A

`U_(n+2)`

B

`U_(n+1)`

C

`U_2U_(n+1)`

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC FUNCTIONS

    PATHFINDER|Exercise QUESTION BANK|68 Videos

  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    PATHFINDER|Exercise QUESTIONBANK|25 Videos

Similar Questions

Explore conceptually related problems

If u_(n)=2 cos n theta , then show that u_(n+1)= u_(1)u_(n)-u_(n-1) , hence, show that 2 cos 5 theta= u_(1)^(5)- 5u_(1)^(3)+ 5u_(1)

If u_n=cos^ntheta+sin^ntheta then 2u_6-ku_4+1=0 then the numerical quantity k must be equal to

If n is a positive integer and U_(n) = (3 + sqrt5)^(n) + (3 - sqrt5)^(n) , then prove that U_(n + 1) = 6U_(n) - 4U_(n -1), n ge 2

Let A=((1,0,0),(2,1,0),(3,2,1)) . If u_(1) and u_(2) are column matrices such that Au_(1)=((1),(0),(0)) and Au_(2)=((0),(1),(0)) , then u_(1)+u_(2) is equal to :

In a geometric series, the first term is a and common ratio is rdot If S_n denotes the sum of the terms and U_n=sum_(n=1)^n S_n ,then r S_n+(1-r)U_n equals a. 0 b. n c. n a d. n a r

If U_n=int_0^pi(1-cosnx)/(1-cosx)dx , where n is positive integer or zero, then show that U_(n+2)+U_n=2U_(n+1)dot Hence, deduce that int_0^(pi/2)(sin^2ntheta)/(sin^2theta)=1/2npidot

If U_n=(sqrt(3)+1)^(2n)+(sqrt(3)-1)^(2n) , then prove that U_(n+1)=8U_n-4U_(n-1)dot

If u_n=sin^("n")theta+cos^ntheta, then prove that (u_5-u_7)/(u_3-u_5)=(u_3)/(u_1) .

If u_n=sin^("n")theta+cos^ntheta, then prove that (u_4-u_6)/(u_2-u_4)=1/2 .

If u_n=sin ^n alpha+cos^nalpha then show that, the value of 6u_4-4u_6 is independent of alpha .

PATHFINDER-TRIGONOMETRIC RATIOS AND IDENTITIES-QUESTION BANK
  1. The value of sin20^@sin 40^@sin 60^@sin 80^@ is

    Text Solution

    |

  2. In a triangle ABC,sin A-cos B=cosC,then angle B is

    Text Solution

    |

  3. If Un=2 cosntheta then U1Un-U(n-1) is equal to

    Text Solution

    |

  4. Ifpilt2thetalt(3pi)/2then sqrt(2+sqrt(2+2cos4theta) is equal to

    Text Solution

    |

  5. Ifcos5theta=acos^5theta+bcos^3theta+ccostheta then c is equal to

    Text Solution

    |

  6. Let n be an odd integer if sin ntheta=underset(r=0)oversetnsumbrsin^rt...

    Text Solution

    |

  7. if x in (-pi/2,pi/2) then the minimum value of cos^2x+(secx/4)is

    Text Solution

    |

  8. The number of real solutions of the equation sin (e^x)=2^x+2^(-x) is

    Text Solution

    |

  9. The maximum value of 4sin^2x+3cos^2x+sin(x/2)+cos(x/2) is

    Text Solution

    |

  10. If sin^2theta=sinphi cosphi then the value of cos2theta is

    Text Solution

    |

  11. If in a triangle ABC,sin^2A+sin^2B+sin^2C=2 then the triangle is alway...

    Text Solution

    |

  12. If alpha and beta are solutions ofsin^2x+asinx+b=0 as well as ofcos^2x...

    Text Solution

    |

  13. If thetane(2n+1)pi/2. ninI, then the least value of (sintheta+cosecthe...

    Text Solution

    |

  14. If in a triangle ABC ,(sin A+sin B +sin C)(sinA+sinB-sin C)=3sinAsinB ...

    Text Solution

    |

  15. Let n be a fixed positive integer such that sin(pi/(2n))+cos(pi/(2n))=...

    Text Solution

    |

  16. Minimum value of4x^2-4x abs(sintheta)-cos^2theta is equal to

    Text Solution

    |

  17. The maximum value of the expression abs(sqrt((sin^2x+2a^2))-sqrt((2a^2...

    Text Solution

    |

  18. For 0ltthetaltpi/2 the solution of underset (m=1)overset6sumcosec(thet...

    Text Solution

    |

  19. If tanalpha and tanbeta be the roots of the equation (x^2+px+q=0) then...

    Text Solution

    |

  20. If tan9theta=3/4(where0ltthetaltpi/18)then the value of (3cosec 3theta...

    Text Solution

    |