Home
Class 11
MATHS
Prove that: i) sin20^(@)sin40^(@)sin60...

Prove that:
i) `sin20^(@)sin40^(@)sin60^(@)sin80^(@)=3/16`
ii) `sin10^(@)sin50^(@)sin60^(@)sin70^(@)=sqrt(3)/16`
iii) `sin20^(@)sin40^(@)sin80^(@)=sqrt(3)/8`

Text Solution

AI Generated Solution

Promotional Banner

Topper's Solved these Questions

  • TRIGNOMETRIC FUNCTIONS

    NAGEEN PRAKASHAN ENGLISH|Exercise EXERCISES 3F|26 Videos

  • TRIGNOMETRIC FUNCTIONS

    NAGEEN PRAKASHAN ENGLISH|Exercise EXERCISES 3G|12 Videos

  • TRIGNOMETRIC FUNCTIONS

    NAGEEN PRAKASHAN ENGLISH|Exercise EXERCISES 3D|45 Videos

  • STRAIGHT LINES

    NAGEEN PRAKASHAN ENGLISH|Exercise Exercise|207 Videos

Similar Questions

Explore conceptually related problems

Prove that sin10^(@) sin 30^(@) sin 50^(@) sin 70^(@)=1/16

Prove that: sin6^(@)sin42^(@)sin66^(@)sin78^(@)=1/16

Prove that : sin60^(@)cos30^(@)+cos60^(@).sin30^(@)=1

Prove that : sin60^(@)=2sin30^(@)cos30^(@) .

Prove that : cos30^(@).cos60^(@)-sin30^(@).sin60^(@)=0

Prove that : cos30^(@).cos60^(@)-sin30^(@).sin60^(@)=0

Prove that sin20^(@)sin40^(@)sin80^(@)=(sqrt(3))/(8)

Prove that: (cos40^(@)+cos50^(@))/(sin40^(@)+sin50^(@))=1

Prove that : (i) sin42^(@)cos48^(@)+sin48^(@)cos42^(@)=1 (ii) cos70^(@)cos20^(@)-sin70^(@)sin20^(@)=0

Prove that sin 20^(@) sin 40^(@) sin 80^(@) = (sqrt3)/(8).

NAGEEN PRAKASHAN ENGLISH-TRIGNOMETRIC FUNCTIONS-EXERCISES 3E
  1. Express each of the following as a sum or difference of sine and cosin...

    Text Solution

    |

  2. Evaluate: sin(521/2)^(@) cos(7(1/2))^(@)

    Text Solution

    |

  3. Prove that: cos(45^(@)+A) cos(45^(@)-A)=1/2 cos2A

    Text Solution

    |

  4. Prove that: cos Acos(60^0-A)cos(60^0+A)=1/4cos3A

    Text Solution

    |

  5. If A=30^(@), show that : sin3A=4sinAsin(60^(@)-A)sin(60^(@)+A)

    Text Solution

    |

  6. Prove that: tan(pi/3-A).tan(pi/3+A)= (2cos2A+1)/(2cos2A-1)

    Text Solution

    |

  7. Prove that: i) sin20^(@)sin40^(@)sin60^(@)sin80^(@)=3/16 ii) sin10...

    Text Solution

    |

  8. Prove that: i) cos10^(@)cos30^(@)cos50^(@)cos70^(@)=3/16 ii) cos20...

    Text Solution

    |

  9. Prove that: tan20^0tan40^0tan80^0=tan60^0

    Text Solution

    |

  10. Prove that: tan(A+B)/(2) + tan(A-B)/(2) = (2sinA)/(cosA+cosB)

    Text Solution

    |

  11. Prove that: i) sin50^(@)-sin70^(@)+sin10^(@)=0 ii) sin(60^(@)+A)+s...

    Text Solution

    |

  12. Prove that: i) sin(5pi)/(18) - cos(4pi)/(9) = sqrt(3)sinpi/9 ii) c...

    Text Solution

    |

  13. Prove that: (sinA+sinB)/(sinA-sinB) = tan((A+B)/(2)). Cot((A-B)/(2))

    Text Solution

    |

  14. Prove that: (sin9A-sin7A)/(cos7A-cos9A) = cot8A

    Text Solution

    |

  15. Prove that: (cos2A+cos3A+cos4A)/(sin2A+sin3A+sin4A)= cot3A

    Text Solution

    |

  16. Prove that: (sin7A-2sin4A+sinA)/(cos7A-2cos4A+cosA)=tan4A

    Text Solution

    |

  17. Prove that: (sin(A+B)-2sinA+sin(A-B))/(cos(A+B)-2cosA+cos(A-B))= tan...

    Text Solution

    |

  18. Prove that (cosA-cosB)^2+(s in A-s in B)^2=4sin^2(A-B)//2]

    Text Solution

    |

  19. show that cos2thetacos(theta/2)-cos3thetacos((9theta)/2)=sin5thetasin(...

    Text Solution

    |