Home
Class 12
MATHS
In any DeltaABC prove by vectors that a^...

In any `DeltaABC` prove by vectors that `a^2=b^2+c^2-2` bc `cos` A.

Promotional Banner

Topper's Solved these Questions

  • VECTORS

    MODERN PUBLICATION|Exercise Exercise|500 Videos

  • UNIT TEST-4

    MODERN PUBLICATION|Exercise EXERCISE|13 Videos

Similar Questions

Explore conceptually related problems

In any DeltaABC prove by vectors that b^2=c^2+a^2-2 ca cos B.

In any triangle ABC, then by vectors, prove that : a=b cos C+c cos B .

In any triangle ABC, then by vectors, prove that : c^2=a^2+b^2-2ab cos C .

In any triangle ABC, prove that cos A= frac{b^2+c^2-a^2}{2bc} .

In DeltaABC, prove that cosA=(b^2+c^2-a^2)/(2b c) by vector method.

In any DeltaABC, 2 [bc cos A + ca cos B+ ab cos C]=

In a triangleABC , prove by vector method that cos2A+cos2B+cos2Cge(-3)/(2) .

In any DeltaABC , prove that a^(3)cos(B-C)+b^(3)cos(C-A)+c^(3)cos(A-B)=3abc

In any triangle ABC, prove that : b^2 sin 2C + c^2 sin 2B = 2 bc sin A .

In any triangle ABC, prove that : (b^2-c^2) cot A + (c^2-a^2)cot B +(a^2-b^2)cotC=0 .

MODERN PUBLICATION-VECTORS-Exercise
  1. Which of the following statements are True or False : If the diagonals...

    Text Solution

    |

  2. Prove that sum of squares of the diagonals of a parallelogram is equal...

    Text Solution

    |

  3. In any DeltaABC prove by vectors that a^2=b^2+c^2-2 bc cos A.

    Text Solution

    |

  4. In any DeltaABC prove by vectors that b^2=c^2+a^2-2 ca cos B.

    Text Solution

    |

  5. In any triangle ABC, then by vectors, prove that : c^2=a^2+b^2-2ab cos...

    Text Solution

    |

  6. Prove that, in any triangle ABC, cos B=(c^2+a^2-b^2)/(2ca).

    Text Solution

    |

  7. With the help of vector method, prove that,cosA=(b^2+c^2-a^2)/(2bc)

    Text Solution

    |

  8. In any triangle ABC, then by vectors, prove that : a=b cos C+c cos B.

    Text Solution

    |

  9. Use vectors to prove that in triangleABC : b=c cos A+a cos C.

    Text Solution

    |

  10. Using vector method prove that cos(A-B)=cosAcosB+sinAsinB

    Text Solution

    |

  11. In any triangle ABC, show that AB^(2)+AC^(2)=2(AD^(2)+BD^(2)) wher...

    Text Solution

    |

  12. Prove that any two edges in a regular tetrahedron are perpendicular.

    Text Solution

    |

  13. In each problem, find the work done by a force vecF acting on a partic...

    Text Solution

    |

  14. In each problem, find the work done by a force vecF acting on a partic...

    Text Solution

    |

  15. Find the work done by the force vecF=hati+2hatj+hatk acting on a parti...

    Text Solution

    |

  16. Find the work done in moving an object along the vector vecd=3hati+2ha...

    Text Solution

    |

  17. A particle acted by constant forces 4 hat i+ hat j-3 hat k and 3 hat...

    Text Solution

    |

  18. Constant forces 2hati-5hatj+6hatk and hati+2hatj-hatk act on a particl...

    Text Solution

    |

  19. Forces of magnitudes 5 and 3 units acting in the directions 6hati + ...

    Text Solution

    |

  20. Which is greater: 45 kg or 4500 g?

    Text Solution

    |