Home
Class 11
MATHS
If cos A+cos B+2cos C=2 then the sides o...

If `cos A+cos B+2cos C=2` then the sides of the ` A B C` are in A.P. (b) G.P. (c) H.P. (d) none

Promotional Banner

Topper's Solved these Questions

  • BASIC MATHS,LOGARITHIM, TRIGNOMETRIC RATIO AND IDENTITIES AND TRIGNOMETRIC EQUATION

    ALLEN|Exercise EXERCISE (S-1)|44 Videos

  • Solutions of Triangle & Binomial Theorem

    ALLEN|Exercise Do yourself -6|4 Videos

Similar Questions

Explore conceptually related problems

In triangle ABC, if cosA+2cosB+cosC=2,t h e na ,b ,c are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If cos2B=(cos(A+C))/(cos(A-C)), then tan A,tan B,tan C are in (a)A.P.(b) G.P.(c) H.P.(d) none of these

In a triangle A B C , if cos A+2\ cos B+cos C=2. prove that the sides of the triangle are in A.P.

If tanbeta=2sinalphasingammacos e c(alpha+gamma), then cotalpha,cotbeta,cotgamma are in (a)A.P. (b) G.P. (c) H.P. (d) none of these

If x,y,z are in A.P. then : yz,zx,xy are in (a) A.P (b) G.P (c) H.P (d) no definite sequence

If cos A+cos B=4sin^(2)((C)/(2)) then prove that sides a,c,b of an triangle ABC in A.P.

If cos A+cos C=2(1-cos B), then a,b,c are in A.P.

If the square of differences of three numbers be in A.P., then their differences re in (A) A.P. (B) G.P. (C) H.P. (D) none of these

In an equilateral triangle, inradius r , circumradius R and ex-radius r_1 are in A.P. (b) G.P. (c) H.P. (d) none of these

ALLEN-SOLUTION AND PROPERTIES OF TRIANGLE-All Questions
  1. In A B C , if r\ : r1: R=2\ : 12\ :5, where all symbols have their us...

    Text Solution

    |

  2. If a , b ,\ A are given in a triangle and c1a n d\ c2 are two possible...

    Text Solution

    |

  3. If cos A+cos B+2cos C=2 then the sides of the A B C are in A.P. (b) G...

    Text Solution

    |

  4. In a triangle A B C ,\ C D is the bisector of the angle Cdot If cosC/2...

    Text Solution

    |

  5. The medians of a A B C are in 9c m ,\ 12 c m\ a n d\ 15 c m respectiv...

    Text Solution

    |

  6. If ' O ' is the circum centre of the A B C and R1,\ R2,\ R3 are the r...

    Text Solution

    |

  7. Two rays emanate from the point A and form an angle of 43 with one a...

    Text Solution

    |

  8. In a A B C ,\ A=pi/3\ a n d\ b : c=2: 3. If tanalpha=(sqrt(3))/5,\ o<...

    Text Solution

    |

  9. The value of (cosA)/(P1)+(cosB)/(P2)+(cosC)/(P3) is

    Text Solution

    |

  10. Statement - I : The statement that circumradius and inradius of a t...

    Text Solution

    |

  11. Prove that : 4\ R\ sin AsinB\ sin C=acosA+b\ cos B+c cosCdot

    Text Solution

    |

  12. If p1,\ p2, p3 are the altitudes of a triangle from the vertices A , B...

    Text Solution

    |

  13. For any triangle ABC, If B=3C, show that cosC=sqrt((b+c)/(4c)) and s...

    Text Solution

    |

  14. A B C is a triangle. D is the mid point of B Cdot If A D is perpendicu...

    Text Solution

    |

  15. Prove that r1+r2+r3-r=4R

    Text Solution

    |

  16. In a Delta ABC, GA,GB,GC makes angles alpha, beta, gamma with each oth...

    Text Solution

    |

  17. In a DeltaABC, the median to the side BC is of length 1/sqrt(11-6sqrt...

    Text Solution

    |

  18. Prove that : (r1)/(b c)+(r2)/(c a)+(r3)/(a b)=1/r-1/(2R)

    Text Solution

    |

  19. Prove that : (tanA/2)/((a-b)(a-c))+(tanB/2)/((b-a)(b-c))+(tanC/2)/((c-...

    Text Solution

    |

  20. Prove that in a triangle (b c)/(r1)+(c a)/(r2)+(a b)/(r3)=2R\ [(a/b+b...

    Text Solution

    |