Home
Class 12
MATHS
If A + B + C = pi " and " cos A = cos B ...

`If A + B + C = pi " and " cos A = cos B cos C, "show that"`
`2 cot B cot C = 1`

Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    CHHAYA PUBLICATION|Exercise Long Answer Type Questions|12 Videos

  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    CHHAYA PUBLICATION|Exercise Multiple Correct Answers Type|5 Videos

  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    CHHAYA PUBLICATION|Exercise Very Short Answer type Questions|23 Videos

  • TRIGONOMETRIC RATIOS OF ASSOCIATED ANGLES

    CHHAYA PUBLICATION|Exercise SAMPLE QUESTIONS FOR COMPETITIVE EXAMS - ASSERTION-REASON TYPE|2 Videos

  • TRIGONOMETRIC RATIOS OF MULTIPLE ANGLES

    CHHAYA PUBLICATION|Exercise Comprehension Type|6 Videos

Similar Questions

Explore conceptually related problems

If A + B + C = pi "and" cos A = cos B cos C, "show that" tan B tanC = 2

If A + B + C = pi " and " cos A = cos B cos C, "show that" tan A = tan B + tan C

If A+B+C=(3pi)/2 , then cos2A +cos2B+cos2C is

If cos A+ cos B + cos C=0 , prove that cos 3A + cos 3B + cos 3C = 12 cos A cos B cos C

If cos A = tan B , cos B= tan C, cos C= tanA , show that sin A= sin B= sin C= 2 sin 18^(@)

If (a + b) tan (theta - phi) = (a-b) tan (theta + phi) " and " a cos 2 phi + b cos 2 theta = c, "show that" a^(2) -b^(2) + c^(2) = 2a cos 2 phi

In the triangle ABC, if cos 3 A + cos 3B+ cos 3C=1 , show that the triangle is obtuse-angled.

If A , Ba n dC are the angels of a triangle, show that |[-1+cos B, cos C+cos B, cos B],[ cos C+cos A,-1+cos A ,cos A],[-1+cos B,-1+cos A,-1]|=0

In any triangle ABC if sin A sin B sin C+ cos A cos B=1 , then show that a:b:c=1:1: sqrt(2) .

In /_\ABC ,Prove that a cos A + b cos B + c cos C = 2a sin B sin C

CHHAYA PUBLICATION-TRIGONOMETRIC RATIOS OF COMPOUND ANGLES-Short Answer Type Questions
  1. Simplify: tan(pi/4 + theta) tan ((3pi)/4 + theta)

    Text Solution

    |

  2. Simplify: sin (B + C) sin (B - C) + sin (C + A) sin (C - A) + sin(A ...

    Text Solution

    |

  3. Find the expansion: sin (A - B + C)

    Text Solution

    |

  4. Find the expansion: tan (A + B - C)

    Text Solution

    |

  5. If sin alpha sin beta - cos alpha cos beta + 1 = 0,"show that", sin (a...

    Text Solution

    |

  6. If A + B = 45^(@), "show that",(1 + tan A) (1 + tan B) = 2 , "hence fi...

    Text Solution

    |

  7. If A + B + C = pi " and " cos A = cos B cos C, "show that" tan A = t...

    Text Solution

    |

  8. If A + B + C = pi " and " cos A = cos B cos C, "show that" 2 cot B c...

    Text Solution

    |

  9. An angle theta is divided into two parts alpha " and " beta such that ...

    Text Solution

    |

  10. If tan theta = (Q sin alpha)/(P + Q cos alpha), "prove that", tan (alp...

    Text Solution

    |

  11. If sin (alpha + beta) = n sin (alpha - beta) " and " n ne -1," prove t...

    Text Solution

    |

  12. If cot alpha cot beta = 3,"show that", (cos (alpha - beta))/(cos (alph...

    Text Solution

    |

  13. Find the value of (sin (alpha + beta))/(sin (alpha - beta)), "given th...

    Text Solution

    |

  14. If 0^(@) < theta < 90^(@) "and" cos theta + sin theta = sqrt2,"find th...

    Text Solution

    |

  15. If tan alpha = (x sin beta)/(1-x cos beta) " and " tan beta = (y sin a...

    Text Solution

    |

  16. If tan theta + tan phi = x "and" cot theta + cot phi = y, "prove that ...

    Text Solution

    |

  17. If tan theta = (2x - K)/(K sqrt3) " and " tan varphi = (xsqrt3)/(2 K-x...

    Text Solution

    |

  18. If cos (theta - alpha) = p " and " sin(theta + beta) = q," show that "...

    Text Solution

    |

  19. Eliminate theta " and " phi sin theta + sin phi = a, cos theta + co...

    Text Solution

    |

  20. Eliminate theta " and " phi tan theta + tan phi = x, cot theta + co...

    Text Solution

    |