Home
Class 12
MATHS
If xcosalpha+ysinalpha=xcosbeta+ysinbeta...

If `xcosalpha+ysinalpha=xcosbeta+ysinbeta=2a` then `cosalpha cosbeta=`

A

`cos alpha + cos beta = (4ax)/(x^(2)+y^(2))`

B

`cos alpha cos beta = (4a^(2)-y^(2))/(x^(2)+y^(2))`

C

`sin alpha + sin beta = (4ay)/(x^(2)+y^(2))`

D

`sin alpha sin beta= (4a^(2)-x^(2))/(x^(2)+y^(2))`

Text Solution

Verified by Experts

The correct Answer is:
A, B, C, D
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC FUNCTIONS AND IDENTITIES

    ARIHANT MATHS|Exercise Exercise For Session 1|10 Videos

  • TRIGONOMETRIC FUNCTIONS AND IDENTITIES

    ARIHANT MATHS|Exercise Exercise For Session 2|10 Videos

  • TRIGONOMETRIC EQUATIONS AND INEQUATIONS

    ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|12 Videos

  • VECTOR ALGEBRA

    ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|9 Videos

Similar Questions

Explore conceptually related problems

If cosalpha+cosbeta=0=sinalpha+sinbeta , then cos2alpha+cos2beta=?

If A=[(0,sin alpha, sinalpha sinbeta),(-sinalpha, 0, cosalpha cosbeta),(-sinalpha sinbeta, -cosalphacosbeta, 0)] then (A) |A| is independent of alpha and beta (B) A^-1 depends only on beta (C) A^-1 does not exist (D) none of these

If cosalpha+cosbeta=a, sinalpha+sinbeta=b, then cos(alpha+beta) is equal to (A) (2ab)/(a^2+b^2) (B) (a^2+b^2)/(a^2-b^2) (C) (a^2-b^2)/(a^2+b^2) (D) (b^2-a^2)/(b^2+a^2)

By geometrical interpretation, prove that (i) sin(alpha+beta)=sin alpha cos beta+sinbeta cosalpha (ii) cos(alpha+beta)=cosalpha cosbeta -sin alpha sinbeta

If tan^(2)alpha=1+2tan^(2)beta , then sqrt(2)cosalpha-cosbeta=?

If cosalpha+cosbeta=0=sinalpha+sinbeta , then prove that cos2alpha +cos2beta=-2cos(alpha +beta) .

If the lines x(sinalpha+sinbeta)-ysin(alpha-beta)=3 and x(cosalpha+cosbeta)+ycos(alpha-beta)=5 are perpendicular then sin2alpha+sin2beta is equal to:

Show without expanding at any stage that: | (1,cosalpha-sinalpha, cosalpha+sinalpha),(1,cosbeta-sinbeta,cosbeta+sinbeta),(1, cosgamma-singamma,cosgamma+singamma)| =2 |(1,cosalpha, sinalpha),(1,cosbeta, sinbeta),(1,cosgamma,singamma)|

If the points A(0,0),B(cosalpha,sinalpha) , and C(cosbeta,sinbeta) are the vertices of a right- angled triangle, then

ARIHANT MATHS-TRIGONOMETRIC FUNCTIONS AND IDENTITIES-Exercise (Questions Asked In Previous 13 Years Exam)
  1. If xcosalpha+ysinalpha=xcosbeta+ysinbeta=2a then cosalpha cosbeta=

    Text Solution

    |

  2. If alpha and beta are non-zero real number such that 2(cos beta-cos al...

    Text Solution

    |

  3. Let -1/6 < theta < -pi/12 Suppose alpha1 and beta1, are the root...

    Text Solution

    |

  4. The value of sum(k=1)^(13) (1)/(sin(pi/4 + ((k-1)pi)/(6))sin(pi/4 + (k...

    Text Solution

    |

  5. Let f : (-1, 1) -> R be such that f(cos4theta) = 2/(2-sec^2theta for t...

    Text Solution

    |

  6. The number of all possible values of theta, where 0 lt theta lt pi, f...

    Text Solution

    |

  7. For 0 lt theta lt pi/2, the solution (s) of sum(m=1)^(6) cosec (the...

    Text Solution

    |

  8. If sin^ 4 x/2+cos^4 x/3 =1/5 then

    Text Solution

    |

  9. Let theta in (0,pi/4) and t1=(tan theta)^(tan theta), t2=(tan theta)6(...

    Text Solution

    |

  10. cos(alpha-beta)=1a n dcos(alpha+beta)=l/e , where alpha,betamu in [-pi...

    Text Solution

    |

  11. If 5(tan^2x - cos^2x)=2cos 2x + 9, then the value of cos4x is

    Text Solution

    |

  12. Let fk(x) = 1/k(sin^k x + cos^k x) where x in RR and k gt= 1. Then f4(...

    Text Solution

    |

  13. The expression (tanA)/(1-cotA)+(cotA)/(1-tanA) can be written as (1) s...

    Text Solution

    |

  14. If a Delta PQR " if" 3 sin P + 4 cos Q = 6 and 4 sin Q + 3 cos P =1 , ...

    Text Solution

    |

  15. If A = sin^2x + cos^4 x, then for all real x :

    Text Solution

    |

  16. Let cos (alpha+beta) = 4/5 and sin(alpha-beta)=5/13 where 0<= alpha,...

    Text Solution

    |

  17. If cosalpha+cosbeta+cosgamma=0=sinalpha+sinbeta+singamma, then which...

    Text Solution

    |

  18. A triangular park is enclosed on two sides by a fence and on the third...

    Text Solution

    |

  19. If 0 lt x lt pi and cos x + sin x = 1/2, then tan x is

    Text Solution

    |

  20. In Delta PQR , /R=pi/4, tan(P/3), tan(Q/3) are the roots of the equati...

    Text Solution

    |