Home
Class 11
MATHS
If cos alpha+ cos beta= a, sin alpha+ si...

If `cos alpha+ cos beta= a, sin alpha+ sin beta= b and alpha- beta= 2 theta`. Then `(cos 3 theta)/(cos theta)=`

A

`a^2+b^2-2`

B

`a^2+b^2-3`

C

`3-a^2-b^2`

D

`(a^2+b^2)//4`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • MULTIPLE & SUBMULTIPLE

    AAKASH SERIES|Exercise PRACTICE SHEET (EXERCISE - II) (LEVEL - II) (More than One correct answer Type Questions)|3 Videos

  • MULTIPLE & SUBMULTIPLE

    AAKASH SERIES|Exercise PRACTICE SHEET (EXERCISE - II) (LEVEL - II) (Linked Comprehension Type Questions)|5 Videos

  • MULTIPLE & SUBMULTIPLE

    AAKASH SERIES|Exercise PRACTICE SHEET (EXERCISE - I) (LEVEL - II) (More than One correct answer Type Questions)|7 Videos

  • MEAN VALUE THEOREMS

    AAKASH SERIES|Exercise PRACTICE SHEET (EXERCISE-I (LEVEL-II (MORE THAN ONE CORRECT ANSWER TYPE QUESTIONS ) )|2 Videos

  • MULTIPLE & SUBMULTIPLE ANGLES

    AAKASH SERIES|Exercise PRACTICE EXERCISE|68 Videos

Similar Questions

Explore conceptually related problems

If cos alpha + cos beta =0 = sin alpha + sin beta " then " cos (alpha - beta )=

If sin alpha = sin beta and cos alpha = cos beta then

If cos alpha + cos beta = 1//2 and sin alpha + sin beta = 1//3, then

If cos alpha+cos beta=0=sin alpha+sin beta , then cos 2 alpha+cos 2beta is equal to

sin alpha=sinbeta, cos alpha=cos beta then

If cos alpha + cos beta = a, sin alpha + sin beta = b and theta is the arithmetic mean between alpha and beta then sin 2 theta + cos 2 theta is equal to

If x= sin alpha + sin betga , y = cos alpha + cos beta tan alpha + tan beta =

If cos alpha + cos beta = 3/2 and sin alpha + sin beta = 1/2 and theta is the arithmetic mean of alpha and beta then sin 2 theta + cos 2 theta

AAKASH SERIES-MULTIPLE & SUBMULTIPLE -PRACTICE SHEET (EXERCISE - II) (LEVEL - I) (Straight Objective Type Questions)
  1. A quadratic equation whose roots are tan22""1^@/2 and cot22""(1^@)/2 i...

    Text Solution

    |

  2. 32sin^(6) 15^@ -48 sin^(4) 15 ^(@) + 18 sin^2 15^@ =

    Text Solution

    |

  3. If cos alpha+ cos beta= a, sin alpha+ sin beta= b and alpha- beta= 2 t...

    Text Solution

    |

  4. If 0 lt x lt pi and cos x + sin x=1/(2) , then tanx =

    Text Solution

    |

  5. sin "" (2pi)/(7) + sin "" (4pi)/(7) + sin "" (8pi)/(7) =

    Text Solution

    |

  6. If sin""(pi)/18 sin""(5pi)/18 sin""(7pi)/18 =

    Text Solution

    |

  7. If cos theta (1) = 2 cos theta (2), then tan (( theta (1) + theta (2)...

    Text Solution

    |

  8. sin^4""(pi)/16+sin^4""(3pi)/16+sin^4""(5pi)/16+sin^4""(7pi)/16=

    Text Solution

    |

  9. The roots of the equation 4x^2-2sqrt5x+1=0 are

    Text Solution

    |

  10. If theta(1) and theta2 are two values lying in [0,2pi] for which tan t...

    Text Solution

    |

  11. cot 15^@ + cot 75^@ + cot 135^@ =

    Text Solution

    |

  12. cot7(1^@)/2-cot37(1^@)/2-cot52(1^@)/2+cot82(1^@)/2 =

    Text Solution

    |

  13. If sin x + "cosec"x + tan y + cot y = 4 where x and y in (0,(pi)/2) ta...

    Text Solution

    |

  14. The value of cot(7pi)/16 + 2cot(3pi)/8 + cot(15pi)/16 is:

    Text Solution

    |

  15. cos ^(3) x sin 2x= sum (x=0) ^(n) a (r) sin (rx) AA x in R, then

    Text Solution

    |

  16. Let f(n)(theta)= tan""(theta)/2(1+sectheta)(1+sec2theta)(1+sec4theta)....

    Text Solution

    |

  17. cos{(2pi)/(2^(64)-1)}cos{(2^2pi)/(2^(64)-1)}......cos{(2^(64)pi)/(2^(6...

    Text Solution

    |

  18. If theta=pi/(2^n+1) then cos theta cos 2 theta cos 2^(2) theta...... ...

    Text Solution

    |

  19. If sinx + cos x = sqrt7/2 where x in 1^(st) quadrant , then tan""(x)/2...

    Text Solution

    |

  20. cosx=(2cosy-1)/(2-cosy) , where x , y in (0,pi) then tan""x/2 cot""(y)...

    Text Solution

    |