Home
Class 12
MATHS
In a DeltaABC, if DeltaC = 60°, then b...

In a `DeltaABC`, if `DeltaC = 60°`, then
`b/(c^(2)-a^(2))+a/(c^(2)-b^(2))=`

A

a+b+c

B

`1/(a+b+c)`

C

abc

D

0

Text Solution

Verified by Experts

We have,
`angleC=60^(@)`
`rArrcosC=1/2`
`rArr(a^(2)+b^(2)-c^(2))/(2ab)=1/2`
`rArra^(2)+b^(2)-c^(2)=ab`
`rArrc^(2)-a^(2)=b^(2)-ab` and `c^(2)-b^(2)=a^(2)-ab`
`rArrb/(c^(2)-a^(2))=1/(b-a)` and `a/(c^(2)-b^(2))=1/(a-b)`
`rArrb/(c^(2)-a^(2))+a/(c^(2)-b^(2))=1/(b-a)+1/(a-b)=0`
Promotional Banner

Topper's Solved these Questions

  • PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM

    OBJECTIVE RD SHARMA|Exercise Section I - Solved Mcqs|95 Videos

  • PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM

    OBJECTIVE RD SHARMA|Exercise SOLVED MCQ|2 Videos

  • PLANE AND STRAIGHT LINE IN SPACE

    OBJECTIVE RD SHARMA|Exercise Chapter Test|31 Videos

  • REAL FUNCTIONS

    OBJECTIVE RD SHARMA|Exercise Chapter Test|60 Videos

Similar Questions

Explore conceptually related problems

In a DeltaABC , if a =2, B = 60°and C =75°, then b=

In a DeltaABC , if A = 45° and C = 60°, then a+ sqrt2C=

In any DeltaABC , prove that ((b^(2)-c^(2)))/a^(2)"sin 2a"+((c^(2)-a^(2)))/b^(2)" sin 2B+"((a^(2)-b^(2)))/c^(2)"sin 2C=0"

In any DeltaABC , prove that (c^(2)-a^(2)+b^(2))tanA=(a^(2)-b^(2)+c^(2))tanB=(b^(2)-c^(2)+a^(2))tanC

In a DeltaABC (bsin(C-A))/(c^(2)-a^(2))+(csin(A-B))/(a^(2)-b^(2))=

In a DeltaABC , (b^(2)-c^(2))/(asecA)+(c^(2)-a^(2))/(bsecB)+(a^(2)-b^(2))/(csecC)=

In DeltaABC , prove that: (b^(2)-c^(2)+a^(2))tanC=(b^(2)+c^(2)-a^(2))tanA

In any DeltaABC , prove that (b^(2)-c^(2))cotA+(c^(2)+a^(2))cotB+(a^(2)-b^(2))cotC=0 .

In a DeltaABC, (c^(2)+a^(2)-b^(2))tanB+(a^(2)+b^(2)-c^(2))tanC=

In a DeltaABC , if A=45^(@) and B=75^(@) , then a+sqrt(2)c=

OBJECTIVE RD SHARMA-PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM-Chapter Test
  1. In a DeltaABC, if DeltaC = 60°, then b/(c^(2)-a^(2))+a/(c^(2)-b^(2))...

    Text Solution

    |

  2. If the sides of a triangle are in the ratio 3 : 7 : 8, then find R : r

    Text Solution

    |

  3. The area of the reactangle polygen of n sides is (where R is the radiu...

    Text Solution

    |

  4. If the angles of a rectangle are 30^(@) and 45^(@) and the included si...

    Text Solution

    |

  5. In a triagnle ABC, angle B=pi/3 " and " angle C = pi/4 let D divide ...

    Text Solution

    |

  6. If A is the area and 2s the sum of the sides of a triangle,then

    Text Solution

    |

  7. If in a triangle ABC, right angled at B, s-a=3, s-c=2, then the values...

    Text Solution

    |

  8. If the sides of a triangle are a, b and sqrt(a^(2) + ab + b^(2)), then...

    Text Solution

    |

  9. In a DeltaA B Csum(b+c)tanA/2tan((B-C)/2)=

    Text Solution

    |

  10. In triangle ABC, angleA=pi/3 and b:c =2:3, tan theta=sqrt3/5, 0 lt the...

    Text Solution

    |

  11. In a DeltaABC, AD is the altitude from A. Given bgtc ,angleC=23^(@) an...

    Text Solution

    |

  12. If the angles A, B, C (in that order) of triangle ABC are in arithmeti...

    Text Solution

    |

  13. If the radius of the incircle of a triangle withits sides 5k, 6k and 5...

    Text Solution

    |

  14. Two sides of a triangle are 2sqrt2 and 2sqrt3cm and the angle opposite...

    Text Solution

    |

  15. In a triangleABC, a=13cm, b=12 and c=5cm The distance of A from BC is

    Text Solution

    |

  16. In a triangleABC,B=pi/8, C=(5pi)/(8). The altitude from A to the side ...

    Text Solution

    |

  17. In a DeltaABC, A=(2pi)/3, b-c=3sqrt3 cm and area(DeltaABC)=(9sqrt3)/2 ...

    Text Solution

    |

  18. In DeltaABC if a=(b-c)sectheta then (2sqrt(bc))/(b-c)sin(A/2)=

    Text Solution

    |

  19. In a DeltaABC, (a + b + c) (b + c - a) = lambda bc. (where symbols ha...

    Text Solution

    |

  20. If in DeltaABC, a=2b and A=3B, then A is equal to

    Text Solution

    |

  21. Let the angles A , B and C of triangle A B C be in AdotPdot and let b ...

    Text Solution

    |