Home
Class 12
MATHS
Prove that, in any triangle ABC, cos C=(...

Prove that, in any triangle ABC, `cos C=(a^2+b^2-c^2)/(2ab)`.

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

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

Prove that in any triangle ABC,c=a cos B+b cosA

Prove that in any triangle ABC , c = a cos(360-B) + b cos(360-A)

In any triangle ABC, prove that : (cosA)/a+ (cosB)/b+(cosC)/c= (a^2+b^2+c^2)/(2abc) .

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

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

In a triangle ABC, 2ca sin frac(A-B+C)(2) =

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

Statement I In any triangle ABC a cos A+b cos B+c cos C le s. Statement II In any triangle ABC sin ((A)/(2))sin ((B)/(2))sin ((C)/(2))le 1/8

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

MODERN PUBLICATION-VECTORS-Exercise
  1. Prove that, in any triangle ABC, cos C=(a^2+b^2-c^2)/(2ab).

    Text Solution

    |

  2. Represent graphically a displacement of 40 km, 30^o west of south.

    Text Solution

    |

  3. Represent the following graphically a displacement of : 40 km, 30^@ ea...

    Text Solution

    |

  4. Represent the following graphically a displacement of : 40 km, 30^@ ea...

    Text Solution

    |

  5. Classify the following measure as scalar and vector: 10 Kg

    Text Solution

    |

  6. Classify the following measure as scalar and vector: 40^o

    Text Solution

    |

  7. Classify the following measure as scalar and vector: 2 meters north-w...

    Text Solution

    |

  8. Classify the following measure as scalar and vector:40watt

    Text Solution

    |

  9. Classify the following measure as scalar and vector: 10^(-19)coulomb

    Text Solution

    |

  10. Classify the following measure as scalar and vector: 20 m/s^2

    Text Solution

    |

  11. Classify the following measures as scalars and vectors: 1000 cm^3

    Text Solution

    |

  12. Classify the following measures as scalars and vectors: 10 N

    Text Solution

    |

  13. Classify the following measures as scalars and vectors: 30 km/h

    Text Solution

    |

  14. Classify the following as scalar and vector quantities: time period

    Text Solution

    |

  15. Classify the following as scalar and vector quantities: distance

    Text Solution

    |

  16. Classify the following as scalar and vector quantities: force

    Text Solution

    |

  17. Classify the following as scalar and vector quantities: velocity

    Text Solution

    |

  18. Classify the following as scalar and vector quantities:work done

    Text Solution

    |

  19. In the figure identify the following vectors : Co-initial.

    Text Solution

    |

  20. In the figure identify the following vectors : Equal.

    Text Solution

    |

  21. A girl walks 4 km towards west, then she walks 3 km in a direction 30^...

    Text Solution

    |