Home
Class 12
MATHS
In a triangleABC, prove by vector method...

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

Promotional Banner

Topper's Solved these Questions

  • PRODUCT OF VECTORS

    ARIHANT MATHS|Exercise Exercise For Session 1|13 Videos

  • PRODUCT OF VECTORS

    ARIHANT MATHS|Exercise Exercise For Session 2|19 Videos

  • PROBABILITY

    ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|55 Videos

  • PROPERTIES AND SOLUTION OF TRIANGLES

    ARIHANT MATHS|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|21 Videos

Similar Questions

Explore conceptually related problems

Prove by vector method that cos(A+B)=cos A cos B-sin A sin B

Prove by vector method that cos(A+B)cos A cos B-sin A sin B

In triangleABC , prove that cos^(2)A+cos^(2)B+cos^(2)Cge(3)/(4) .

In o+ABC, prove that cos A+cos B+cos C<=(3)/(2)

In any triangle ABC, prove that following: (cos^(2)B-cos^(2)C)/(b+c)+(cos^(2)C-cos^(2)A)/(c+a)+(cos^(2)A-cos^(2)B)/(a+b)=0

In any triangle ABC, prove that: (1+cos(A-B)cos C)/(1+cos(A-C)cos B)=(a^(2)+b^(2))/(a^(2)+c^(2))

In any triangleABC , prove that a^(2)=(b+c)^(2) -4b(c)cos^(2)(A/2)

In triangleABC, cos((A-B)/(2))=

If triangleABC is a right angled at A, then: cos^(2)B + cos^(2)C=

In DeltaABC , prove that: cos2A+cos2B-cos2C=1-4sinAsinBcosC

ARIHANT MATHS-PRODUCT OF VECTORS-Exercise (Questions Asked In Previous 13 Years Exam)
  1. In a triangleABC, prove by vector method that cos2A+cos2B+cos2Cge(-3)/...

    Text Solution

    |

  2. Let O be the origin and let PQR be an arbitrary triangle. The point S ...

    Text Solution

    |

  3. Let O be the origin and OX, OY, OZ be three unit vectors in the direct...

    Text Solution

    |

  4. Let O be the origin, and O X , O Y , O Z be three unit vectors ...

    Text Solution

    |

  5. Let a, b and c be three unit vectors such that atimes(btimesc)=(sqrt(3...

    Text Solution

    |

  6. Let vec(a) , vec(b) and vec(c) be three non-zero vectors such that no ...

    Text Solution

    |

  7. If a, b and c are unit vectors satisfying |a-b|^(2)+|b-c|^(2)+|c-a|^(2...

    Text Solution

    |

  8. The vector(s) which is/are coplanar with vectors hat(i)+hat(j)+2hat(k)...

    Text Solution

    |

  9. Let vec a =hat i+hat j+hat k,vec b=hat i -hat j+hat k and vec c =hat ...

    Text Solution

    |

  10. Two adjacent sides of a parallelogram ABCD are given by vec(AB)=2hati+...

    Text Solution

    |

  11. Let P, Q, R and S be the points on the plane with position vectors -2h...

    Text Solution

    |

  12. If a and b are vectors in space given by a=(hat(i)-2hat(j))/(sqrt(5)) ...

    Text Solution

    |

  13. If veca,vecb,vecc and vecd are unit vectors such that (vecaxxvecb)*(...

    Text Solution

    |

  14. The edges of a parallelopiped are of unit length and are parallel to ...

    Text Solution

    |

  15. Lelt two non collinear unit vectors hata and hatb form and acute angle...

    Text Solution

    |

  16. Let the vectors PQ, QR, RS, ST, TU and UP represent the sides of a reg...

    Text Solution

    |

  17. The number of distinct real values of lambda, for which the vectors -l...

    Text Solution

    |

  18. Let veca,vecb,vecc be unit vectors such that veca+vecb+vecc=vec0. Whic...

    Text Solution

    |

  19. Let A be vector parallel to line of intersection of planes P1 and P2. ...

    Text Solution

    |

  20. Let a=hat(i)+2hat(j)+hat(k), b=hat(i)-hat(j)+hat(k), c=hat(i)+hat(j)-h...

    Text Solution

    |

  21. If vec a , vec b and vec c are three non-zero, non coplanar vecto...

    Text Solution

    |