Home
Class 11
MATHS
For alpha , beta in R, prove that (cos a...

For `alpha , beta in R`, prove that `(cos alpha + cos beta )^(2)+ (sin alpha + sin beta )^(2)=4cos^(2). ((alpha-beta))/(2)`

Promotional Banner

Topper's Solved these Questions

  • MULTIPLE & SUBMULTIPLE ANGLES

    AAKASH SERIES|Exercise EXERCISE 3.1 ( LONG ANSWER QUESTION )|9 Videos

  • MULTIPLE & SUBMULTIPLE ANGLES

    AAKASH SERIES|Exercise ADDITIONAL EXERCISE |15 Videos

  • MULTIPLE & SUBMULTIPLE ANGLES

    AAKASH SERIES|Exercise EXERCISE 3.1 (VERY SHORT ANSWER )|7 Videos

  • MULTIPLE & SUBMULTIPLE

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

  • MULTIPLE PRODUCT OF VECTORS

    AAKASH SERIES|Exercise PRACTICE EXERCISE|62 Videos

Similar Questions

Explore conceptually related problems

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

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

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

2 sin^(2) beta + 4 cos( alpha+ beta) sin alpha sin beta + cos ( 2 alpha + 2 beta )=

If cos alpha + cos beta + cos gamma = 0 sin alpha + sin beta + sin gamma , Prove that cos^(2) alpha + cos^(2) beta + cos^(2) gamma = 3/2 = sin^(2) alpha + sin^(2) beta + sin^(2) gamma .

[(cos alpha-cos beta)+i(sin alpha-sinbeta)]^n+[(cos alpha-cos beta)-i(sin alpha-sin beta)]^n=

If sin alpha + sin beta = a , cos alpha + cos beta = b " then sin ( alpha + beta ) =

AAKASH SERIES-MULTIPLE & SUBMULTIPLE ANGLES-EXERCISE 3.1 ( SHORT ANSWER QUESTION )
  1. If none of 2A, 3A is an odd multiple of pi/2 then prove that tan 3A ...

    Text Solution

    |

  2. For alpha , beta in R, prove that (cos alpha + cos beta )^(2)+ (sin al...

    Text Solution

    |

  3. IF theta is not an integral muliple of pi/2, prove that tantheta+2ta...

    Text Solution

    |

  4. Prove that (cos3A + sin3A)/(cosA - sin A) = 1+ 2sin 2A.

    Text Solution

    |

  5. Prove that cot(pi/4-theta)=(cos2theta)/(1-sin2theta) and hence find th...

    Text Solution

    |

  6. If theta lies in third Quardrant and Sintheta=(-4)/5. Find the values ...

    Text Solution

    |

  7. If 450^(@)lt theta lt 540^(@) and Sintheta=12/13 then calculate "Sin"t...

    Text Solution

    |

  8. Prove that (sin2A)/((1+Cos2A))((CosA))/(1+CosA)=tan.A/2

    Text Solution

    |

  9. (Cos^(3)theta-Cos3theta)/(Costheta)+(Sin^(3)theta+Sin3theta)/(Sintheta...

    Text Solution

    |

  10. Show that CosA=(Cos3A)/(2Cos2A-1). Hence find the value of Cos15^(@)

    Text Solution

    |

  11. Show that sin A= (sin 3A) /(1+2 cos 2A). Hence find the value of sin 1...

    Text Solution

    |

  12. Prove that tanalpha=(Sin2alpha)/(1+cos2alpha) and hence deduce the val...

    Text Solution

    |

  13. In aDelta^("le") ABC If "Tan"(A)/(2)=(5)/(6),"Tan"(B)/(2)=(20)/(37) th...

    Text Solution

    |

  14. If Costheta=5/13 and 270^(@)ltthetalt360^(@). Evaluate "Sin"theta/2 an...

    Text Solution

    |

  15. If 180^(@)lt thetalt270^(@) and Sintheta=(-4)/5 calculate "Sin"theta/2...

    Text Solution

    |

  16. Show that sin""(pi)/5.sin""(2pi)/5.sin""(3pi)/5.sin""(4pi)/5=5/16.

    Text Solution

    |

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

    Text Solution

    |

  18. Prove that "Cos"^(2)(pi/10)+"Cos"^(2)((2pi)/5)+"Cos"^(2)((3pi)/5)+"Cos...

    Text Solution

    |