Home
Class 14
MATHS
Let alpha, beta be such that pi lt alpha...

Let `alpha, beta` be such that `pi lt alpha -beta lt 3 pi.`
If `sin alpha + sin beta =- (21)/(65) and cos alpha + cos beta =- (27)/(65) and ` if the value of `cos "" (alpha - beta)/(2) =(-a)/(sqrtb),` then `a xx b=`

A

`(-3)/(sqrt(130))`

B

`(3)/(sqrt(130))`

C

`(6)/(65)`

D

`(-6)/(65)`

Text Solution

Verified by Experts

The correct Answer is:
A, 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

Let alpha, beta be such that it pi < alpha - beta <3 pi . if sin alpha + sin beta =-21/65 and cos alpha+cos beta = -27 / 65 then the value of cos ((alpha-beta)/2) is

Let alpha, beta be such that pi lt alph-betalt3piif sin alpha+sinbeta=-21/65and cos alpha+cos beta =-27/65, then the value of cos""(alpha-beta)/(2), is

Le alpha and beta be such that pi

If sin alpha+sin beta=a and cos alpha-cos beta=b then

sin alpha+sin beta=(1)/(4) and cos alpha+cos beta=(1)/(3) The value of cos(alpha+beta) is

If sin alpha+sin beta=a and cos alpha-cos beta=b then tan((alpha-beta)/(2))=

sin alpha + sin beta = a, cos alpha + cos beta = b rArr sin (alpha + beta)

pi

ADVANCED MATHS BY ABHINAY MATHS ENGLISH-TRIGONOMETRY -EXERCISES (Multiple Choice Questions)
  1. If asectheta+btantheta+c=0andpsectheta+qtantheta+r=0, then (br-qc)^(2)...

    Text Solution

    |

  2. If P=acos^(3)x+3acosx.sin^(2)xandQ=asin^(3)x+3acos^(2)x.sinx, then (P+...

    Text Solution

    |

  3. Let alpha, beta be such that pi lt alpha -beta lt 3 pi. If sin alpha...

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |

  18. 7cosectheta+24sectheta=25cosecthetasectheta, then costheta=?

    Text Solution

    |

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

    Text Solution

    |

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

    Text Solution

    |