Home
Class 11
MATHS
In any triangle A B C ,sin^2A-sin^2B+sin...

In any triangle `A B C ,sin^2A-sin^2B+sin^2C` is always equal to (A) `2sinAsinBcosC` (B) `2sinAcosBsinC` (C) `2sinAcosBcosC` (D) `2sinAsinBsinC`

Text Solution

Verified by Experts

`sin^2A-sin^2B+sin^2C`
As `sin^2A-sin^2B = sin(A+B)sin(A-B) `, it becomes,
`=sin(A+B)sin(A-B) +sin^2C`
`=sin(pi-C)sin(A-B) +sin^2C`
`=sinCsin(A-B) +sin^2C`
`=sinC(sin(A-B)+sinC)`
`=sinC(sin(A-B)+sin(pi-(A+B))`
`=sinC(sin(A-B)+sin(A+B))`
...
Promotional Banner

Topper's Solved these Questions

  • STRAIGHT LINES

    CENGAGE PUBLICATION|Exercise All Questions|486 Videos

Similar Questions

Explore conceptually related problems

In triangleABC sin^2A+sin^2B =sin^2C then angleC=

In triangle ABC if sin^2B+sin^2C=sin^2A then

In triangleABC,sin((B+C)/2) =

If in a triangle ABC, sin^2A+sin^2B+sin^2C=2 then the triangle is always

In any triangle ABC show that b^2sin2C+c^2sin 2B=abc/R

Prove that in a A B C ,sin^2A+sin^2B+sin^2C<=9/4dot

In any triangle ABC prove that sin2A+sin2B+sin2C=(abc)/(2R^3)

sin^2A+sin^2(A-B)+2sinAcosBsin(B-A) is equal to

In any triangle ABC, prove that sin^3Acos(B-C)+sin^3Bcos(C-A)+sin^3Ccos(A-B) = 3sinAsinBsinC

In triangle ABC, (i) asin(A/2 + B) = (b+c) sin A/2

CENGAGE PUBLICATION-TRIGONOMETRIC FUNCTIONS-All Questions
  1. Prove that sum(k=1)^(n-1)(n-k)cos(2kpi)/n=-n/2, wherengeq3 is an int...

    Text Solution

    |

  2. If (tan(ln6)dottan(ln2)dot"tan"(ln3))/(tan(ln6)-tan(ln2)-"tan"(ln3))=k...

    Text Solution

    |

  3. In any triangle A B C ,sin^2A-sin^2B+sin^2C is always equal to (A) 2s...

    Text Solution

    |

  4. If cot^2Acot^2B=3, then the value of (2-cos2A)(2-cos2B) is

    Text Solution

    |

  5. If tanalpha=m/(m+1) and tanbeta=1/(2m+1) . Find the possible values o...

    Text Solution

    |

  6. If u=sqrt(a^2 cos^2 theta + b^2sin^2theta)+sqrt(a^2 sin^2 theta + b^2 ...

    Text Solution

    |

  7. The value of sin^2 12^0+sin^2 21^0+sin^2 39^0+sin^2 48^0-sin^2 9^0-sin...

    Text Solution

    |

  8. The value of f(x)=x^4+4x^3+2x^2-4x+7, when x=cot((11pi)/8) is

    Text Solution

    |

  9. Prove that sqrt3 "cosec" 20^@-sec20^@=4

    Text Solution

    |

  10. If (1+sint)(1+cost)=5/4 then find the value of (1-sint)(1-cost)dot

    Text Solution

    |

  11. If alpha,beta,gamma,delta are the smallest positive angles in ascendi...

    Text Solution

    |

  12. (sin^2A-sin^2B)/(sinAcosA-sinBcosB)is equal to

    Text Solution

    |

  13. If cos25^0+sin25^0=p , then cos50^0 is

    Text Solution

    |

  14. The value of cot((7pi)/16)+2cot((3pi)/8)+cot((15pi)/16) is (a)4 (b...

    Text Solution

    |

  15. If t a n^2theta=2t a n^2varphi+1 , prove that cos2theta+sin^2phi =0.

    Text Solution

    |

  16. If tanA.tanB=1/2,t h e n(5-3cos2A)(5-3cos2B)= (a)2 (b) 8 (c) 12 ...

    Text Solution

    |

  17. If cos(alpha-beta)=3sin(alpha+beta),t h e n 1/(1-3sin2alpha)+1/(1-3sin...

    Text Solution

    |

  18. The value of cos^2 10^0-cos10^0cos50^0+cos^2 50^0 is equal to

    Text Solution

    |

  19. If cosα+cosβ= 3/2 ​ and sinα+sinβ= 1/2​ and θ is the arithmeti...

    Text Solution

    |

  20. Let a ,ba n dc be real numbers such that a+2b+c=4 . Find the maximum v...

    Text Solution

    |