Home
Class 11
MATHS
cos 20^@ cos 40^@ cos 80^@=...

`cos 20^@ cos 40^@ cos 80^@=`

Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC FUNCTIONS

    CBSE COMPLEMENTARY MATERIAL|Exercise VERY SHORT ANSWER TYPE QUESTIONS|20 Videos

  • STRAIGHT LINES

    CBSE COMPLEMENTARY MATERIAL|Exercise SECTION-D (LONG ANSWER TYPE QUESTIONS )|23 Videos

Similar Questions

Explore conceptually related problems

Prove that cos 20^@ cos 40^@ cos60^@ cos80^@=1/16

The value of cos 20^(@) cos 40^(@)cos 60^(@) cos 80^(@) is equal to

Prove that: cos20^(@)cos40^(@)cos80^(@)=(1)/(8)

Prove that: cos20^(@)cos40^(@)cos80^(@)=1/8

Prove that a) (sin3A + sinA)sinA+(cos3A-cosA) cosA=0 b) cos20^(@)cos40^(@)cos80^(@)=1/8 c) (sin8thetacostheta-sin6thetacos3theta)/(cos2thetacostheta-sin3thetasin4theta) = tan2theta

What is cos80^@ + cos 40^@ - cos20^@ equal to ?

Find the value of cos20^@. cos40^@. Cos60^@. Cos80^@

if sin2A=2sin A cos A and sin20^(@)=K then the value of cos20^(@)cos40^(@)cos80^(@)cos160^(@)-

Prove that cos 20^(@)cos40^(@)cos60^(@)cos80^(@)=(1)/(16)

CBSE COMPLEMENTARY MATERIAL-TRIGONOMETRIC FUNCTIONS -SHORT ANSWER TYPE QUESTIONS
  1. find the value ofsqrt3cosec20^(@)-sec20^(@)

    Text Solution

    |

  2. The value of co s pi/5 co s.2pi / 5 c o s 4pi / 5 co s 8pi / 5 =

    Text Solution

    |

  3. cos 20^@ cos 40^@ cos 80^@=

    Text Solution

    |

  4. Find the general solution of the following equations sin 7x = sin 3...

    Text Solution

    |

  5. Find the general solutions of each of the following equations : (1) ...

    Text Solution

    |

  6. Solve sin x-3 sin 2x + sin 3x = cos x -3 cos 2x + cos 3x.

    Text Solution

    |

  7. Draw the graph of cosx, sin x and tan x in [0, 2pi]

    Text Solution

    |

  8. Draw sin x, sin 2x and sin 3x on same graph and with same scale

    Text Solution

    |

  9. Evaluate(i) cos 36^(@) (ii)tan((13pi)/(12))

    Text Solution

    |

  10. cos^4(pi/8)+cos^4((3pi)/8)+cos^4((5pi)/8)+cos^4((7pi)/8)=

    Text Solution

    |

  11. If tanA=tanB=xa n dcotB-cotA=y , prove that cot(A-B)=1/x+1/y

    Text Solution

    |

  12. If (sin(x+y))/(sin(x-y))=(a+b)/(a-b) , then show that (tanx)/(tany)=(...

    Text Solution

    |

  13. if coxx=cosalpha.cosbeta then prove that tan((x+alpha)/2)*tan((x-alpha...

    Text Solution

    |

  14. If tan(picostheta)=cot(pisintheta), then cos(theta-(pi)/(4))=pm(1)/(2s...

    Text Solution

    |

  15. If sin(theta+alpha)=aa n dsin(theta+beta)=b , prove that cos2(alpha-be...

    Text Solution

    |

  16. Find the range of 5 sin x – 12 cos x + 7

    Text Solution

    |

  17. If alpha and beta are the solutions of the equation atan theta+ b s...

    Text Solution

    |

  18. If alphaa n dbeta are the solutions of the equation at a ntheta+bs e c...

    Text Solution

    |

  19. 2 sin^(2) beta + 4 cos( alpha+ beta) sin alpha sin beta + cos ( 2 alph...

    Text Solution

    |

  20. If 81^(sin^2 x) + 81^(cos^2 x) = 30, where (pi//2) le x le pi, then x ...

    Text Solution

    |