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|Exercise Solved Examples And Exercises|381 Videos

Similar Questions

Explore conceptually related problems

In any triangle ABC ,c^2 sin 2 B + b^2 sin 2 C is equal to

In a triangle ABC, sin^(2)A + sin^(2)B + sin^(2)C = 2 , then the triangle is

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

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

In a triangle ABC , if cos A cos B + sin A sin B sin C = 1 , then a:b:c is equal to

If in triangle A B C ,/_C=45^0 then find the range of the values of sin^2A+sin^2Bdot

In a triangle ABC, prove that b^(2) sin 2C+c^(2) sin 2B=2bc sin A .

In any triangle prove that a^2 =(b+c)^2 sin^2 (A/2) +(b-c)^2 cos^2 (A/2)

In a triangle ABC, if sin A sin(B-C)=sinC sin(A-B) , then prove that cos 2A,cos2B and cos 2C are in AP.

CENGAGE-TRIGONOMETRIC FUNCTIONS-Solved Examples And Exercises
  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^2cos^2 theta +b^2 sin ^2 theta ) + sqrt( a^2 sin^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. Find the value of sqrt3" cosec "20^(@)-sec 20^(@)

    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 (a)"tan"(A-B) ...

    Text Solution

    |

  13. If cos25^0+sin25^0=p , then cos50^0 is (a)sqrt(2-p^2) (b) -sqrt(2...

    Text Solution

    |

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

    Text Solution

    |

  15. If tan^2theta=2tan^2phi+1,t h e ncos2theta+sin^2phi equals (a)-1 (...

    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^(-1)x-cos^(-1)y/2=alpha,t h e n4x^2-4x ycosalpha+y^2 is equal t...

    Text Solution

    |

  18. The value of cos^2 10^0-cos10^0cos50^0+cos^2 50^0 is equal to 4/3 (b)...

    Text Solution

    |

  19. If 2|sin2alpha|=|tanbeta+cotbeta|,alpha,beta in (pi/2,pi), then the v...

    Text Solution

    |

  20. In A B C , if (sinA)/(csinB)+(sinB)/c+(sinC)/b=c/(a b)+b/(a c)+a/(b c...

    Text Solution

    |